A or B

Period was September 1st through the 6th.

Had unprotected sex with A on September 6th and he pulled out. I checked myself after we were done and didn't smell or feel any Of his semen.

Had unprotected sex with B on September 8th through the rest of the month. Was highly active between the 8th and 20th. Did it multiple times and he came inside every single time.

According to my period app which every month i get my period when it says i should based on a 28 day cycle......i was fertile from September 10th through 15th and ovulated on September 15th. Which is the time I was with B who came inside.

Would you say A or B is the father?