At what point in your pregnancy did you have the ultrasound that said your due date was November 14? How far along were you in weeks?
The last guy is more likely to be the dad, but all of the guys are in range, since sperm can live 5-6 days in your reproductive tract.
See a lawyer or a legal-aid clinic (many are associated with law schools, call the dean's office and ask if they have a low-cost clinic) and see what the laws in your area can do for you to get all three of the men summoned to take a DNA test. They don't get to just shrug and say they don't want to, the court will require them to.
It's in the interests of the state for dads to be identified and to help pay for their child's expenses. Your lawyer will know what to do to make the tests happen.