okay, so i have started what i thought was my period 2 weeks early. i am on a birth control pill. well i didn't even know i was pregnant if i was and i took a pregnancy test yesterday and it came back negative. i had heavy bleeding and back pain on the first day but it has slowly tapered off. i have been passing little what look like to be clots. can anyone help determine what this is before i go to my gynecologist?