27 weeks pregnant. they told her that her conceive date was september 9th but she had sex with someone one else on the 19th. any was he is the father?

Trust date given: If your doctor gave you conception date, i would trust this date. If the given conception date falls between the time of intercourse with two different men, you might consider paternity testing.

Conception: If she is exactly 27 weeks pregnant, she should have ovulated on approximately 12/26. There is no way she conceived on Sept. 9 or any other time in Sept. She would have conceived sometime around Christmas.