re the father if the gestational age was that low at
the end
of november. Keep in mind that
gestational age starts from
the last
menstrual period, so the actual conception date is generally around 2 weeks later. That would make conception most likely in mid october, not september. Ultrasound scans can be off by a week or so, but generally not much more than that.
Still, the only way to be 100% sure is to do a dna test when the baby is born. Good luck.