Please help! What is going on?

[zynox]

I am on the pill. I am very regular never had a problem with my period. Last month I had sex and 1 day later I took my pill and threw up, but since I threw up I took another one. Later that month I got sick and had to took ibuprofeno even though it doesn't mess with my pill I took it 3 hours apart of the pill. Then it was my period due, I had the usual cramps showing that my period was coming, but this time it was very very light almost nothing on the pad, when I wiped there was only dark brown "blood" but this "period" was very light and weird never had something like that, only when I wiped I could see a little red blood but barely anything. I freaked out. Then my period stopped. Then I started throwing up like crazy couldnt eat anything had no appetite, went to the doctors and he said I had gastritis. But I took two home pregnancy tests and they came negative. Now I am experiencing in the middle of my cycle (my period is not due in 11 days) when I pee I wipe and it seems to be a little brown like little brown discharge. This month I ate really bad since I coudnt eat, lost weight and I'm just really stressed because of this. Could I be pregnant? What is this brown discharge when I wipe? Please help.