Hello,

I 19 and I usually have irregular periods since I'm under a lot of stress. I haven't had my period for about 2-3 months.. On February 4th during sexual intercourse the condom broke basically came off with out us noticing. I took a pregnancy test on February 21 or 22 and it came out negative, but latley I have been feeling a bit sick nasuea and small headaches. I can hardly sleep as well. Might there be a chance I am pregnant.

Yes. The first test may have been taken too early. I'd wait a few more days and take another test. Make sure you take it in the morning using first morning urine.