Hello, I had a 1.5 day period which is very unusual for me, it was red the first day and brown the next. I have been feeling sick everyday around 5pm. Having extreme nausea but no throwing up, cramping in my uterus, and headaches followed with mild back pain. And I'm not wanting to eat much, due to my stomach feeling uncomfortable all day. I took a pregnancy test last week and it was negative, but could I be pregnant?