Not feeling pregnant.

I'm 15 weeks pregnant and I feel completely normal. The only difference is how emotional I get so easily. But my body doesn't feel pregnant at all. I have a tiny bump but I'm wondering if other women actually felt pregnant at 15 weeks. I know she's in there and she's fine, I had an ultrasound 2 weeks ago and they said she was growing perfectly and everything looked great. I just feel like I should be feeling pregnant. Or at least different, I don't know. :(