Who's the dad?

Hi girls my friend is in a big dilemma about dates from when she conceived her baby.

She has short cycles roughly around 24/25 days long meaning she would ovulate a little earlier than someone with a 28 day cycle.

Her and he partner broke up August time and she had a period on September 4th..

She slept with someone else on the 24th September

She then briefly remembers coming on her period on the 28th September(she tracks her cycles on a period app- and it says she come on the 28th(heavy with cramps) to till the 1/2October.

Her and her partner got back together and slept together unprotected(done the business inside😂) on the 6,7,8th October..(her period app said her ovulation day was the 8th October)

She got a really faint positive on the 19th October. Had a scan on the 11th of January and they dated her as 14+6 weeks. She is now currently 22 weeks.

She keeps overthinking that it could be the other mans baby and is making herself ill with worry as it was a drunken mistake. I want to put her mind at rest.

Her estimated due date is July 6th x