vaginal pain??!

Nothing nasty or anything but my boyfriend and I had sex and once he was in there and got to a certain point inside it hurt unbearably. Like it felt like my cervix had gotten narrow and was extremely tight. That happens often sometimes and I asked him what it felt like and he said it was just really really tight. Do you ladies know what causes that or is it normal? Also I'll note I get yeast infections probably more often than most women because little miss lady down there doesn't agree with just about any kind of soap at all and was gonna ask could that have something to do with the swelling/tightness.