Thoughts?

I've been having some really weird symptoms. I took a pregnancy test 3 days ago (just routine because it was my time to test) and it was negative. My period started 2 days ago (2 days early) and had already stopped. Then this morning I was sitting on the balcony eating an apple and drinking water and had to rush inside because I felt so nauseated. I dry heaved 3 times and then everything was completely normal. I have had a cold this past week so that could be why my stomach is upset but I was wondering if anyone knew what was going on with me?