Its not typical to get pg the day you get off ur period. More than likely its ur bf. just be honest with him. And next time be carefull of who u let inside of you with no protection.your blessed with a baby but by the grace of god ur lucky all u got was pregnant.
You have two possible candidates for a father. Like the first poster said there is sperm involved even when a guy does not finish. Any time you have unprotected sex there is a risk. If you need to know you are going to have to wait until baby is born and get a paternity test.
The other could be the father even though he didn't *** because there is sperm in pre-*** & it only takes ONE