Anyone else have this problem?!!?

Yesterday I wanted to get it on with my man (sorry don't know how to be more secretive) anywho and when it came to actually doing it, it hurt! A LOT!  I don't know why though. I've never been in that much pain before. Him and I are both clean so it shouldn't be an STI and my pregnancy test was negative and i wasn't dry so idk what it could be... Any suggestions?! Might need to see a doctor...?