If you're a smaller girl [thin/short], then you may simply have skipped your period. It's normal. After so many pregnancy tests, I'd say you weren't pregnant, but going to the doctor was the right thing to do.

I am having the same situation. I have no pregnancy symptoms except dizziness from time to time, tiredness and increased headaches but these could also be signs of my migraines. I took 2 pregnancy test one at the doctor (before period due date) and one at home (after expected period) and they both were negative. I have not had my period yet.. I was on antibotics when I think that if I was pregnant it could have happen. Is there still a possiblity I could be pregnant and I just maybe need to get a blood test pregnancy test done?