naseated, vomiting, cramps, light period, and a negative hpt could I still be pregnant?

I have been having cramps and nausea with some vomiting, and food cravings, getting nausios from smells, and my last normal period was the first of february. I had light bleeding that was a different color than normal, I took 2 hpt that came up negative, 1 inbetween them that had a faint positive, so that is when I took the third and it came up negative. I also had a tubal ligation 3 years ago. I have all the symptoms of being pregnant but I am not so sure. Anyone have an Idea?

CAN ANYBODY TELL ME WHY I AM STILL HAVING MENSTRUAL CRAMPS AFTER MY MENSTRUAL HAS WENT OFF? I WAS SUPPOSED TO HAVE MY PERIOD ON THE 16TH OF APRIL BUT IT CAME ON THE 9TH OF APRIL. IT LASTED FOR 3DAYS WHICH IS UNUSUSAL IT USUSALLY LASTS 7 DAYS.

The same thing has happened to me!!!! I got brown stuff at the time my period was suppost to show- then bled bright red blood for 3 days then it went back to brown and now nothing and I feel like my period is coming because I have cramps and mood swings galore!