Pain during Sex

Me and my partner used to have sex regularly, but lately I've been experiencing pain on the left side of my uterus during intercourse, but not all the times I'm having sex. Only like if I start doing it too often. I googled it and it says that it could be psychological, (fear to get hurt while having intercourse). Should I go to the doctor? I think my partner is getting irritated bc he's all ready to go when I sometimes cannot tolerate the pain :( and he's end up with blue balls multiple times now