Help!!!

My birth control was all messed up and I had sex without a condom. I'm going on 5 days late but I have a mixture of brown, light pink, and bright red blood. It is super light to where it's only on the toilet paper it's not in my underwear or anything. I started bleeding immediately after I had sex today. I took a pregnancy test after about 12-14 days after intercorse and it came back negative. I was going to take a few more on Sunday when I was done with my sugar pills. However, I feel super super sick all throughout the day, some smells make me gag and want to throw up, my lower back is super super sore, I feel hungry all the time, but my boobs aren't sore. Please help!