My period went off on march 8 my due date is around December 9th or 10th I had sex with a guy on march 13 17 23 26 but I had sex with a different guy on April 9 who is the baby dad and when did I get pregnant

You will only know who the father is after the baby is born and a DNA test is done.

Is there another way to tell before the baby comes

Not really, any tests before are dangerous for the baby and would not be done just to tell paternity.

So after the baby is born, you have them both tested.
** I was at the lab today where it was DNA test day, for paternity.
Dozens of men all being mouthy about "it ain't theirs"
They worked me in for a blood test for my doctor.

Try this Just for fun though. You do need a DNA test.

Pregnancy Calculator for Conception Gestation & Due Dates : American Pregnancy Association