I had the same problem too, at 34 weeks it was the opposite now it seems like i have to go more to the bathroom, i guess its the prenatals i only take them 3 times a week and i dont feel as constipated as before
I'm 33 weeks And I'm having that problem too.
It's very common to experience constipation during pregnancy.
The best thing you can do is to make sure you are getting at least 64oz of water daily, stool softener and try Apple or prune juice if you still can not find relief talk to your doctor about switching prenatals, the iron in them can be very constipating