In need of help

Ra

Me and my ex had unprotected sex for the first time in 9months

I start my period in 7 days

My period is really un normal it sometime lasts 3-4 days but not any longer than that and I have super bad cramps some times it comes early sometimes it comes late it just comes and goes ...I also have cyst on my ovaries && I’m not on birth control what possible chance do I have of pregnancy