thanks i appreciate the helpful information i think im going to get a dna test done to be 100% sure
If your only two possible dates were March 31 and April 2, the difference between March 31 and April 2 is too short of a time to say it is one guy or the other. But if you are sure you conceived no earlier than the 20th of April, and had not had sex with anyone else but your boyfriend since March 31, it is probably your boyfriend's. A DNA test is never a bad idea in circumstances like this.
From your due date it is likely you conceived around April 20th or so, give or take a few days. I would say your current boyfriend is most likely the father, but with those dates being so close, you might want to have a dna test done once the baby is born to be sure. Good luck.