Doctors are wrong?

Megan

So I’m 2 weeks late for my period, and I’ve been throwing up and I’ve been getting sick for about three weeks. Some cramps. I feel like I have pregnancy symptoms. So I went and got a blood test done and it said negative.. the doctor said I actually lost 8lbs in 3 weeks. So They gave me some anti nausea medicine and sent me home. I’m not taking the medicine. But could it be possible that I’m pregnant and for some reason it didn’t show on the blood test?