The effects of the "Morning After" Pill

I- have no idea what's going on. I don't understand if this is a side effect or the way it works. I currently can not acquire birth control because I'm only 17 and I'm to afraid to be open about my sex life with my parents. So while my boyfriend and I had sex, my period had just ended and we got lost in the feeling and had sex without protection. The only times we've ever had sex without a condom was when I was on my period with large amounts of bleeding present so there was no scare of- him not pulling out in time. 
Now- I have taken the pill before ( about 3-4 times to be safe). THIS TIME my period had just ended 3 days prior- and it's back. I started bleeding heavily last night and I woke up terrified to see blood everywhere I had no idea what's going on. I really don't know if this is a side effect or if the pill does this or is my body messed up. I just need feedback and help.