can penis size affect pregnancy?

My boyfriends penis is around 5inches, and therefore I cannot feel it deep inside me when it's all the way in.. however, when he finishes it is always inside me, but I never feel like the cum has traveled. This sounds crazy but I feel like it makes sense and a larger penis when all the way in you can feel? Ladies I hope you understand what I mean- that feeling that it's almost hitting the bottom of your stomach? Surely the sperm would be ejaculating closer to the uterus?