Who is the dad here?

Last period was Jan 30th and cycle is about 29 days long. Projected ovulation was February 13th.

Girl had sex the weekend prior on the 6th/7th with "Joe" he pulled out.

Girl had sex the a few days within the week and on the weekend of the 13th with "Matt". He didn't pull out.

Also, had sex again with "Joe" the 20/21st of that same month. But girl got a positive pregnancy test on the 26th.

Who do you think the dad is?