Well I've been vomiting a lot frequently, certain foods make me vomit or just nauseous, period was four days late I got it yesterday & it was heavy but now it's light, sort of pink, I get headaches stomach pains tired a lot back pain I took a pregnancy test 2-3 days ago & it was negative I did have protected sex. What's going on? Last week I had a pain under my left boob & I would get severe cramps but I don't know why. Can I get some help please..