I'm 22 weeks now and my bby girl moves up a storm. I can see and feel her moving inside of my belly. If you're less than 20 weeks it feels like little flutters or bubbles in your belly. After that you'll feel your angel's movements and they become stronger week by week.
Most women say it feels like flutters or butterflies. When I realized that it was baby moving it felt like bubbles in my tummy. That was at about 20 weeks. I didn't actually see my tummy move with his movements until like 28 or 29 weeks. You may not realize it's baby moving at first until you feel that same feeling all the time then it'll dawn on you. Lol
To me it was obvious that I was feeling a kick and full on movement from my daughter. That was around 23 weeks. When I was 18 weeks is when I felt flutters but was unsure. Once I got to 23 there was a huge difference in the movement and it was consistent.