On the portal in the pink line above your story is the number of reads. Sometimes it takes a little while for the reads to show, but it definitely shouldn’t take more than 24 hours normally to update reads. You can also see the number of reads above your avatar on the app (for total reads of all stories).
I’m not saying this happened, but if you’re doing R4R I would suggest asking them to send you 1 screen shot from each chapter they read. While I’m sure most people read when they say they will, not everyone is super honest when about the R4R.