By "questionable," I meant two things. One is that home tests aren't certified by the courts to determine paternity, their accuracy statistics aren't perfect. The other is that for some women on this site (not all), doing a DNA test doesn't relieve their fears. They come back with "But what if the test is wrong!?!?!" This doesn't happen when the women test with both guys and get a positive for one and a negative for the other, but it can sometimes happen to women who only test with one guy. They just start second-guessing.
Some questions: does the baby look like either guy when they were babies? Are you getting tested for purposes of child support? Does your boyfriend know there is a question about the baby's paternity? Are you testing with both guys? Are you going to a lab certified by the courts, or just doing a drugstore test? The worst thing is to test with a home test with only one guy, because the results of home tests can be so questionable that sometimes woman worry that they didn't really get an accurate answer, and the guy doesn't want to test again.
meant to say, "that *could* put you back into the range where it would have been your boyfriend." The margin for error is wide, it includes both guys.
Hi, Vegas, you'll need to do a DNA test. Your ultrasound could seem to suggest you conceived close to the time that you had sex with your ex, but when an ultrasound is in the 14th week, it can be more than a week off if used for purposes of trying to determine the date of conception. That puts you back into the range where it would have been your boyfriend, thanks to you having sex "around the time" of August 9 and the long life of sperm in a woman's reproductive tract. If you want to be the most sure, do a DNA test with both men; a drugstore test would work unless you are doing it for purposes of child support, or if you only intend to test with one guy. In the latter cases, you would need to go to a certified lab.