I've been feeling nausea, sleepy, moody, and experiencing little headaches. Is there a possibility that I could be pregnant?

If you've had sex, then yes, there's a possibility. No one online can diagnose you though, you need to get a pregnancy test.

Yes I've had unprotected sex and I did take a test and it came back negative. Do I need to wait and take another in another week or 2

Probably. Have you missed a period yet?

No I don't come on until the end of the month

Most tests aren't accurate until the time you expect your period. I'd wait until you actually miss it, if you do.

Are you trying to get pregnant?

Ok. Thank you