Going crazy

So i either conceived on 13th or 20th of September ( soon to find out ). Green circled ones is the dates i had intercourse with my now fiance, he finished in me on all those days. The purple circled one 11th was the day i had sex with my ex ( biggest mistake of my life, it was just for once and he pulled out). Is there a chance that the 11th of September sex might be the father ?.