I would say that the first guy is definitely Daddy
I would suggest a DNA test. My gf has 2 babies, both while using a condom and birthcontrol so that is not always 100%. Plus sperm can survive up to 5 days in you, even if he said he didn't release some still does get released and you can get pregnant from it.
DNA testing is the only way you will know for sure.
You really need a dna test, especially since you had sex with both close together. Its really the only way to know for sure.
When I calculate all of it it seems to be the first guy because I had sex with the other one i believe around August 5th and when I went for the second test which was positive I was already 8 weeks almost 9 idk in so confused idk what to do :(