You should see a doctor for persistent dizziness. While pregnant women do experience dizziness it is never to the extent you're talking about and usually not experienced in early pregnancy. If you have negative tests and your period is back on schedule then you're most likely not pregnant and a doctor needs to diagnose you for the dizzy spells.
Dizziness can be caused by a lot of things. I am not sure if I read your last post but it is highly unlikely that you are pregnant if you got your period. If you are still worried you can take a home pregnancy test... Try drinking more water and resting more and that might help with the dizziness too... I hope you feel better soon!