I'm 15 years old, I wonder if I'm likely to be pregnant!

Good evening, well my case is the following I'm 15 years old, and I wonder if I have a chance of being pregnant! Last month my monthly bleeding came day: 08/08 I interrupted taking 2 anti-conceptions in a day, I did this for 3 days (act unthought). Then my monthly bleeding came on 16/08 and remained until 22/08 ... This month it came on 13/09 and ended on 09/09, "coming very little and with a tone (black) on 9/19/09, my cycle deregulated a lot I believe, I had sexual intercourse without any type of condom on September 22nd, and he ejaculated in! Is there any possibility of pregnancy? I await the answer ... Thank you in advance!