What Causes Irregular Periods And Spotting?

Hi I have a question I ve been having irregular periods since last month, I had I can say spotting last month 5 days before my regular period but it was just for like 4 days I m guessing , it stopped before my regular would come and I was expecting my period and I didn t get it til a few days later which was the 28 th. And this month I was expecting my period on the 28 again and today this afternoon when I got home from my boyfriends house I had to go pee and I wiped, it was heavy blood and its still heavy and not only that I got it again 5 days early before my regular period I ve had sex this morning with my boyfriend I mean we been having unprotected sex for month or maybe more and I don t know , am I pregnant?