Am I Pregnant

Brittney
Okay so the last time I had my period was in the middle or end of January. Last month it did not come. I had Sex with my ex boyfriend on feb. 7.. My period never came last month but I had spotting every day up to today since then. I took two preg. Test which both were negative. I had no symptoms of pregnancy either. Last night I begin to feel nauseous but my stomach was not hurting I still feel mastoid today but I'm able
To keep my food down. I know that I normally get this way before my period comes on, but it's now 21 days late! Help please?! Also is this signs of a miscarriage?