I need someone who feels the same!

I'll be 16 weeks tomorrow and I feel nothing. I don't feel pregnant, I'm not showing, I can still sleep on my stomach. I'm overweight to begin with but still. Every now and then I get cramps, but I think it's from gas because right after the cramps come I have the urge to pass gas. At the 12w6d ultrasound baby was hopping around like crazy with a strong BPM of 163. I'm 18 years old, should I worry at all from lack of symptoms? I have a very low risk pregnancy, I've just never been so concerned in my whole life.