PLZ HELP!!

Marissa

So I got off my period on the 4th ..

Well just this past week I've been feeling nauseas and I've been cramping like crazy and have been getting more headaches than usual. I took a pregnancy test and it came up negative. My friend told me it could be a cyst being some symptoms are very similar. I got it checked out and nothing! No cyst UTIs nothing. I'm going crazy right now as to why I'm having these crazy symptoms but no answers!! Any feedback?!