Yeah it is. It’s actually more normal when you just start getting it in the very beginning since your area is adjusting to getting your period. It’s also very common if you exercise a lot and this also causes you to loose it for a month to 3 or more. I’m not entirely sure why this is but it occurs when your other systems are working while on ur period.
Mine is odd too though. When I played sports, it skipped for 2-3 months because my coaches made us workout 4-5 times a week of hardcore running and lifting. Plus when I first got my period, which was at age 10 years old, it was very inconsistent. So it is.