Who turned out to be the father
You really need to do a DNA test. Both November 29 and December 1 are well within the range for conception dates. And in the eleventh week there is a margin for error anyway of almost a week when using ultrasounds to try to determine conception. In short, you just don't have enough information that is accurate and not subject to second-guessing. ("My cycles have been getting longer," "I think August 23" and "him peeing in between the courses" are just not enough to rule anyone out.)
If you are trying to hide the need for a DNA test from your boyfriend, at least get one with the other guy. You can do a drugstore test but if you do, realize you have to get together with him, do the swabs, and immediately (without either person handling the package out of each other's sight) mail the package together, because neither of you should have ANY doubt about the other faking the test (you with your boyfriend's swab or him with some friend's). Because people handle the swabs wrong, drugstore tests are not as accurate as a test at a certified lab (which I strongly recommend) but it doesn't sound like you are going to go to a lab with this guy no matter what I suggest, so getting a drugstore test will at least ease your mind if the guy comes up negative. If you handle the swabs properly and mail everything immediately, that takes care of almost all possibility for error even on a drugstore test. In the end, you do need to go to a certified lab with your boyfriend, especially since you'll probably need DNA evidence if you file for child support, but also so this will not be on your mind. (And because it is only morally correct to know for sure who the child's father is, of course.) I'm sorry that you're in this spot.
In the meantime, if you have any newborn-baby pictures of your boyfriend, compare them to baby pictures of your newborn child. Sometimes that helps a lot to ease your mind, my husband's baby pix and my son's looked identical. Don't compare the baby to a picture, compare a photo of the baby to a photo of your boyfriend as a baby. It makes resemblances more clear.