hes probably the dad :] and your probably feeling guilty
im 16 too and 19 weeks pregnant with the love of my life
and btw even with a condom u can get preg

based on your cycle being an average (typical) 28 days and that your period was due on april 13th then you were likely at your most fertile march 29th and past (likely) fertility by april 8th (this does not mean everyone is safe at this time just based on an average cycle).

without any additional dates (ie last 3-4 periods, or likely date of conception based on ultrasound or likely due date based on ultrasound) it is hard to say anymore.

my opinion is that your boyfriend is most likely to be the father.

I can empathize with you Kelly. I'm in a similar situation. If you are your bf are still together that's good. I'm 26 and single and choose to be that way because I think stress will take a toll on me and my baby. From your post I realize that you had sex the same day as I did March 29, 07 with a friend used a condom and the friend claimed the condom broke and some prefluids might have gotten out. This was during a separation from my bf. Then my bf came back in my life and we had unprotected sex on April 1 but he didn't ejaculate inside but on April 3 he did. My period was due April 22 but nothing showed up. I did a pregnancy test April 24 and found out that I was 4 weeks pregnant. Over and over I keep telling myself it has to be my ex bf because my period had just ended March 28 (saw the last dry spot on March 29). So I can understand that you are scared. Try not to get worked up. Think about you and your baby's health. Best wishes to you and your blessing.