am I pregnant ? is it my period ?

Hello , I've been on and off my BC pills and had unprotected sex over 4 times in 2 weeks . the last time was on my ovulation day ( according to my calendar). I took my BC pill that day immediately right after but not the next day nor the day before. I've been experiencing cramps (mild, nothing serious) , went from spotting (pink , light) to heavy bleeding ( but less than my real period) , gas , bloating... this has been going on like two days after my ovulation. I'm still bleeding ( 3rd day) and my period is due for two more weeks. what's going on exactly ? does anyone have an idea ?