Well, no, there is no other way to tell when the unprotected sex is only 2 days apart and close enough to when you would be expected to ovulate that both guys' sperm would be alive and viable in your body at that time. You can get a DNA test either before or after the baby is born, with doing it before being a lot more costly but obviously you would know much sooner. Can the two guys and you split the cost of a prenatal DNA test? Each of them would do a cheek swab and you would get a blood draw (from your arm). Otherwise the three of you should test after the baby is born.