Burns after sex

Idk what is causing it. When we are into it I’m not dry so idk what else it could be? I tell him so go slow and when he sticks it in it sometimes feels uncomfortable. It burns like crap when I pee afterwards also. It goes away within a few minutes but it’s still very uncomfortable. I’m 15 weeks pregnant and I’ve been to the doctor of course they swab and make sure everything is ok but I’ve recently got checked for a uti it was negative. Tested for STDs and it was negative.. so idk maybe yeast infection?