Negative test

Brianna

Ok ladies. So my period was suppose to start Dec. 23 and it still has not. I’ve taken 2 pregnancy tests and they were both negative. I’ve been having some cramping, feeling nauseous a lot and losing my appetite just about every time i eat. I go in Tuesday January 2nd for a pregnancy test. If it comes out negative again what could it be? Ive never been this late maybe two days at the most.