So I usually hate pregnancy in stories only for the fact that most of them are unrealistic and/or don’t make sense, and even though you’re focusing on solely teen pregnancy I’m glad that you’re asking for advice to make your story as realistic as possible.
My Story
This is literally like the entire story of my first pregnancy so it’s pretty long.
I don’t really consider myself a teen mom, but I did have a somewhat teen pregnancy because I had become pregnant at 19 and then had my first child at 20. My then boyfriend, now fiancé, and I had this…connection. Even to this day I just feel a connection with him that I can’t even explain. But anyways, it was my idea to stop being careful. I knew we ran the risk of pregnancy, but I didn’t think it would really happen, until it did not long later (we are both extremely fertile🙃). I also was not very educated on ANYTHING s*x related. My mom was very closed off on those topics and I usually felt like she didn’t have time to listen to me or would judge me. My dad was more open and easier to talk to, but as a girl, it was hard to tell my dad about everything, ya know?
I didn’t realize I was pregnant until I was 8 weeks along. I missed my period but didn’t pay much attention cause it was already irregular. When it was technically 2 weeks late, I started feeling…funny. So I took a test, and it was positive. I will remember that moment forever. I knew instantly my whole world was about to change. I texted my fiancé (who was working at a job that required him to be away for an entire week at a time) and told him. I don’t really remember much after because I was still reeling from shock. Sometime after, I went to work and I texted my parents and said I had to tell them something. I knew they would bring it up then, so there was no way for me to get out of it.
When I came back home (I was living with my parents and my fiancé was staying with us too bc of how infrequently he was home) and told them, I felt the mood shift. They were not happy. I wasn’t expecting them to be over joyed, but it was still such a fucking hard thing for me to do. BUT, they were still supportive of me. And they all provided me the opportunity to become a stay at home mom and raise my child to the best of my abilities. My mom and/or dad took me to every. Single. Appointment because my fiancé was never home during the week bc of his job. Even though they weren’t very happy about the overall situation, I could tell, after seeing their faces when we heard the babies heartbeat for the first time, that they were going to be great grandparents who loved the baby so much.
Moving along, my pregnancy was pretty normal in my opinion. I was very petite from being active in sports my whole life, so I was healthy and in shape. I was also working two jobs at this time. At one of my jobs, a woman came up to me, noticed I was pregnant, and then asked me WHY IM SO SMALL AND IF MY BABY AND I WERE HEALTHY???!!!?!!?!?? Pregnant woman can’t do anything right when it comes to size. If you’re “too big”, you let yourself go and get asked if you’re having twins. If you’re too small, you’re “unhealthy”. Excuse me ma’am but I’m eating 3 times a day with small snacks in between, I’m a naturally small person so stfu pls😊
The only “complication” I had was when the nurse screwed up my blood pressure and even though I HEARD HER say “whoops” and redo it, they scared me into thinking I had preeclampsia and I had to have weekly appointments where I was hooked up to a machine and they monitored my childs heartbeat for 20 freaking minutes -_-
I had morning sickness, not bad enough to throw up, but I had to carry a bucket with me when I worked first shift lol. I would ACTUALLY throw up if I was in the backseat of a car. I had to be either driving or front passenger. (Not long after finding out I was pregnant, my fiancé, his friend snd his friends gf went to the beach. We woke at 3am snd I felt terrible. I had to sit in the back and I kid you not, I threw up at least every half hour for the ENTIRE 4 hour car ride. By the time we got to the beach, my body was in so much pain, I couldn’t stand up straight because it felt like someone was stabbing my stomach). My only real cravings were cheese, nachos and soup. Nothing weird or crazy like you see on tv.
My parents helped me transform my room into a nice little bedroom/nursery. They took me shopping, helped me make a registry, and my mom planned a nice baby shower for me. Having their presence and being so active was so nice considering my fiancé couldn’t be with me.
I worked one of my jobs that was an hour away until a month before my due date (I couldn’t make it to work fast enough until I was about to pee my pants lol) and I worked my local job until the day of my due date, and then my mom forced me to stop working. She was worried id go into labor and wouldn’t be able to leave the store cause I was the only one there…plus I worked until 10 at night so yeah 
I ended up going OVER my due date by 9 days and my baby was showing NO SIGNS of coming (I think I psychologically tricked myself into delaying labor because I was so scared of the pain). So I had an appointment planned on a Tuesday to have my baby. My fiancé was able to work locally until my appointment, so he came with. I requested that the doctor break my water because I didn’t want to take medicine to start my labor. They noticed that she had a bowel movement already because of how overdue I was, so they gave me 24 hours to get her out because inhaling poopy water isn’t exactly good for the baby
Both of my parents and my fiancé were with me for the entire labor, and I NEEDED each one of them desperately. My mom walked with me and provided the support and knowledge that she wished she had during her three (traumatic) labors. My dad used his tough love to tell me I didn’t need the epidural, that I worked this hard to do everything right for my baby. (No epidural was part of my birth plan, nothing against those who use it). And my fiancé, who was a bit overshadowed by my parents, but was still present snd helpful in any way he could, nonetheless.
I had my child, healthy and beautiful, and it was. A moment I will never forget after 11 hours of labor. Every one in the room telling me how proud they were, my mom crying, my fiancé crying (my dad cried later when he was holding Chloe and she opened her eyes and looked at him for the first time:wink:)…I truly felt like a rockstar. News of my natural delivery spread through the nurses ward, and after I was cleaned up and ready to be taken to my new room, they all lined up outside and cheered for me
I was still high off the adrenaline of just having a baby, so I’m not even kidding when I say I felt like a celebrity walking the red carpet. It was literally the best moment of my life.
Not even my fiancé’s terrible mom (who literally barged into the room and wanted to see what was going on while I was literally pushing my baby out) could ruin the moment.
Once in my new room, my parents eventually left to go home. My fiancé stayed with me, until he got a call from his work FORCING him to leave. He only got to spend 3 FREAKING HOURS with me and our new baby until he had to leave for work, or be fired. Chloe was under his health insurance so he had no choice but to go. I had her at 9pm, he left me at 12am. I had to spend that first night alone, with a baby I didn’t even know yet…exhausted, tired, and not really feeling like much of a rockstar anymore. On top of breastfeeding which we were severely struggling with. I suddenly felt really alone until my dad came back the next morning, and then my mom came after she got off work and then spend the next night with me.
My fiancé wasn’t even home to come home from the hospital with us. And let me tell you, we are both so bitter about it. He left that job not long after, and is now at one that he was actually able to be with for, and take off a week after having our second child.
Post child birth, life has been full of ups and downs. Our relationship suffered, it flourished, we’ve learned more about each other. We argue a lot, but we only want to be with each other. I’m glad for that. I’ve lost myself, largely because I didn’t have much of a chance to explore myself before having a baby, but my life and situation could be much worse. Part of me feels like being a mom was my calling in life, and this is what I was meant to do. Being a mom makes me feel fulfilled.
Not everyone feels like that, nor wants to feel like that, and that’s okay. So keep that in mind whilst writing your story 
• My advice when writing your story, is try not to follow the stereotypical things that you see in movies or other episode stories. Not everyone is supportive. I’m lucky with my parents and one brother being excited for the baby, but my youngest brother despised the new change coming. It took him years to come around, and now he enjoys time with both of my children.
• Don’t use stereotypical “screaming” during child birth. A lot of women portrayed in movies scream like maniacs and use it as an excuse to boss the father around, or be flat out rude. That’s not always true, as everyone handles the pain differently. I was calm for both of my natural child births. The only tile I raised my voice at my fiancé was during my first child’s birth when he ate a Reese’s fast break snd then breathed in my face lol ew!
• don’t be afraid to create unusual pregnancy symptoms, such as my example of extreme motion sickness. Not every one has throw up morning sickness, or craves pickles and ice cream
my only real cravings for my first was cheese, nachos, hot wings and soup. For my second it was garlic powder on everything, cheese and more cheese. (Can you believe, both of my kids are obsessed with cheese?
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• do show that before during and after pregnancy is a struggle, no matter how positive your situation is. Whether there’s an unsupportive family member, the father isn’t in the picture, you don’t know who you are anymore, you never wanted the baby etc. there’s always something that makes it not quite right.
• do show relationships with the in laws. Most times, in laws are difficult to deal with. My MIL is the absolute worst, and that became apparent before my daughter was even born. She would later send me harassing texts, complain about me, be rude, trash talk me and just all around make life difficult all because I didn’t I cater to her and visit her with the baby every single day.
• do show the decision between breast and bottle feeding. I suffered through 5 months of pain, cracked and bleeding nipples before I could finally reach my goal of 1 year breastfeeding with my daughter. I also successfully breastfed my son for 1 year. But the choice between the two is a very hot topic, and mothers who nurse in public (like me) are likely to be shamed for it and told to stop asking for attention/put the boobs away or cover up. Even when I read pregnancy stories, they almost NEVER show or even talk about feeding the baby.
I’ve been working on this for like an hour and a half now lmao so if I think of anything else I’ll edit it in, and I’m also open to pm’s with questions as well. I can also share my experience with my second child, if you wish, as that was a completely different experience. Just keep in mind that every person, every situation, every pregnancy and every child is completely different, and this can be a dent I’ve topic for some people, so don’t be afraid to step away from the stereotypes and portray things in a authentic and considerate way 