Sure, it could definitely be something else. Schedule an appointment with your doctor.
That was my first thought too - he's hitting your cervix. Try using extra lubrication and make sure you're very turned on before you start. That should help.
Are you sure it wouldn't be a cyst or something?
It feels quite uncomfortable that I can't relax and enjoy the moment. It feels like a full bladder even though it's not.
I will have my period in a few days and it feels heavy and full in my abdomen right now. I know that could be because my period is coming but now I'm all worried about it. Could it be something else?
Certain positions may be more uncomfortable then others. See if switching it up helps.
It's possible he is just going in too far and hitting your cervix. Also, you should be "in the mood" before he inserts his penis because your cervix will actually move further up making it more comfortable for you. Different positions will help with this...maybe you on top so you can control it?