15 Weeks and nothing!

I'm 15 weeks today and my only symptom is headaches. I have no bump at all and this is my second baby! I even try to feel where he is by pressing and nothing! Not even a hard area! I'm 5'5" and weigh 124 so how is this possible? My last ultrasound was at 12+4 and he was moving and doing great, I'm just worried because i felt horrible at this point with my first. Anyone else in my shoes?