Penis on the brain??😳😳

Sooooo this may be a dumb question to ask now but I've always been told my mans wang 😜isn't going far enough in to touch my babies... buuuuut, I had my 18wk vaginal US the other day to get my cervix measurements, and almost as soon as she put that thing in, I could see my little girls head pop up on the screen😳😂👶🏼 She's close to my cervix and her brother is right above her, but I was under the impression that a mans penis doesn't even come close to the babies. Now I'm scared to have sex😣😓