Question for anyone whose 18 weeks!

I'll be 18 weeks tomorrow and omg this little girl is so active. My doctor told me I wouldn't really feel her until 20 weeks or so and she's wrong because I can feel her. When Im standing still or when I lay on my back sometimes, she pushes her head or her butt (whatever it is idk) on my left side and I can see it and feel it. It's hard and I look at my belly and my left side is higher than my right. Lol it's the craziest thing. I'm curious if any of you are experiencing this much activity already? It's my first baby so at first I thought it was just gas or something. It's definitely not.