I believe I had food poisoning on Monday and had vomiting and diarrhea all day/night. I ve been gradually feeling better, but still not feeling ready to eat anything more than chicken soup and crackers. But today I got my period (3 weeks early) and its really dark brown almost black. My last period was Nov 26, 2 1/2 weeks ago, and my cycle is usually around 35 days. Whats going on?