I was found late last year to have a dermoid cyst inside of my left ovary. Since it was discovered my period flow has been extremely abnormal ranging from a light 3 day period to once-every-5 months heavy 6 day period. My normal period since I was 15 was extremely trackable, down to the "T" with flow and 6 days on the dot. My boyfriend and I have been having unprotected sex throughout the past few months and timing it around the days that we knew i wouldnt get pregnant. Last month we slipped up and were extremely sexually active during the entire week when i would be extremely fertile and during the ovulation period. Now, I did get my period 4 days late and in a matter of hours it ranged from a brown color to very dark red, almost black. I am scared that with the cyst it is complicating the possiblility of becoming pregnant. And with the cyst I cannot track the regularity of my periods either. Please help. Anyone have any words of advice or comments? I work two jobs so I cant rely on the fatigue to clue me in on a positive pregnancy result. My breasts are usually sore a week before I get my period. Are there any other signs that I can look for? Anything would help...thank you!