So I had my last period in Decembers (6th) and it's been 2 months and still nothing. I have taken many tests and there all negative. I have been feeling like I'm going to throw up, I get light headed, I'm always tired, headaches but my breasts don't hurt at all. I'm just wanting to know why my periods have not come?

That is like saying, my car has gas, why will it not start ?

There are 100's of reasons, and only a doctor, doing medical tests and exam you will know, Perhaps you are pregnant, but a home test is not detecting it yet. That is actually common on some people.