20 wks and no "Kick"

I officially measured 20 weeks at the Dr on Tuesday, which was great, i am right on track... I told the Dr. I was really excited to hear her heart beat again because I have yet to feel her move and everything I read says 16- 20 weeks you can start to feel from teh inside and 20 plus weeks you can feel from the outside... I laid on my back and the Dr. got the doplar thing and we heard out little girls heart beat loud and strong... as the Dr lifted up my shirt, she said oop and looked at me and said " i felt her kick, you didnt feel that?!? " umm no... I am pretty sure i just took a breath haha... so here I am at 20 weeks and still havn't felt her move i am just so excited for that first time... I hear all the time its like a butterfly... well i havnt felt that. I havent felt anything other than pressure in some areas ( which i assume that is her) and then a couple twitch things, but thats it... so I am not worried I know she is doing great.. I am just getting anxious to feel it !