some smell ?

I'm 28 weeks and lately when me and my boyfriend have sex it's a stinch coming from the inside of my vagina. I bathe properly and I'm very healthy and clean but idk what it is. Is it because I'm not able to douche during pregnancy ? Cause I used to douche before I got pregnant but I stopped cause my doctor said so but I'm just trying to figure out why that smell is coming when we have intercourse ?