Lots of details missing because I'm scared someone I know will see this. But help! This is not me. Obviously lol.

Okay. She is due September 5th (give or take a day or two) she had a fiance that she slept with for a year. But on January 9th she slept with her ex husband. Now all of my ttc genies that are so good at this. If she would have conceived on January 9th it wouldn't be possible for her to be early September correct? Mind you the guy she slept in january with is my current fiance and baby's father so this pretty important to me. (We have moved passed the cheating so that's not the issue) so could January 9th sex cause a September 5th due date or did she likely get pregnant before? Sorry if this doesn't make sense. My mind is everywhere.