my boyfriend not going to be a baby daddy

my boyfriend had a one night stand with a woman who waa sleeping around on valentines day only once he has a low sperm count but she called after we met and said she is pregnant ans it may be his but her due date is nov 12th is there even any way ot is his i hope not what do you think. i ask because she had to concieve feb 5th and they didnt have sex until feb 14th