What could this be???? 🤦🏾‍♀️

So this week been very weird ! So my period was three days late. I thought this was my month I was having some of the symptoms of early pregnancy. But also the symptoms of PMS. I can’t tell difference lol anyways I took a test it came out negative. That’s fine, my period can hours after. I knew it was my period it was bright red with clots. So today my period was like that until later on tonight. It stopped out of nowhere!! And as soon as it stop I got EXTREMELY NAUSEOUS to the point I had to leave work because i almost threw up several time. Has this ever happen to them !? Please I need your input. I feel

Like I’m dying