Am i possibly pregnant?

Last month i was on birth control for my first time....but then stoppped this month because i ddnt have money to get another package...& for some reason i had my period twice last month. i was supposed to get it a week ago and havnt gotten it yet..im freaking out. am i pregnant or is has the birth control messed up my whole body system? is it because i got my period twice last month so i wont get it again this month? pls help.