TMI! Sex at 14 weeks

Ok so FTM, probably dumb question. I just had sex for the first time since about 6 weeks pregnant, I'm 14 now. We just did it missionary because he finishes too fast with all others and I usually don't finish period. Well every time he went in deep I felt a ball in my stomach, pretty accurate to baby size, I thought maybe it was just his stomach on mine but I've never felt it before and it was very distinct, was that baby being moved around or just something else?