My period has been orange, brown, and black. no red though, please help?

I started my period three days late. When it came, it was just spots. THen it was brown and kinda black occasionaly, and thick looking. Never once was red, well then it only lasted three days, and then it stopped. Well that was two days ago, i went for a jog today, when i got back i had started agian and it was bright orange and then a pinky kind of orange red and then orange again. For about a month i keep getting sharp pains in my right lower side so i figured it was just my ovaries. Talked to the doc abou that and he said it was probbaly just a cyst. Could that be throwing it off or could i be pregnant? Yes i have had sex, didn't use a condom, but i have an IUD. Could any of these things be throwing me off? I had a friend tell me it could be a tubal pregnancy but i don't see how seeing that i have an IUD. I took a pregnancy test the day of my period (cause i was late) then i started that afternoon. By the way it came out negative, the test that is. Well my third day on my period, which was my last day, i got drunk. I"m so confused and i can't afford a doctor right now. ANy ideas?