I cant cum, penis in va jj type way?

I've never had a orgasm with a partner sticking his thing inside me. i hear lots of women saying they havent either. Okay is it us women or is it really the guys? I've had long and fat/short and fat penis size and still dont recognize if i cum or not. I masterbate alot and i cum easily when i do that but when it comes to partners im not getting it. Im sure it has something to do with the womens state of mind. Which makes sense because all the times i did have sex i was kind of uncomfortable? whether it was wondering if my mom was gonna bust in on us, stuff like that? When the women is comfortable, relaxed, and sexually going then everything is fine. Is this situation normal?