Sex problems need advice

My boyfriend is an average size guy 7 inches quite thick sorry tmi, so I don’t understand why it doesn’t feel good when we have sex It kinda feels like he’s not inside of me but he is like I feel it but I don’t at the time time. Sometimes this happens sometimes doesn’t it really been a problem since I been pregnant but I’ve had the issue before I was pregnant as well just not as much as I do now, I’ve always had a high sex drive still do but sometimes it lowers out of nowhere I don’t think I’m too loose because he always tells me how tight my vagina is in his penis, I want to enjoy sex a y advice?