Generally speaking, when there is a phrase in a post like "According to tests I've done I ovulated on July 20th," with no further information, it's always a good idea to check the basis of the statement. What kind of "tests," were you using ovulation predictor strips at the time? Was it an early ultrasound that gave you a due date without being influenced by the first day of your last period? Was it just from keying in the first day of your last period into an app? If the latter, you might not actually have ovulated when you think you did, and if that is so, you might not have anything to worry about.
From the information you have given, that you ovulated on July 20 and had sex with one guy on the 18th and another on the 21st and 22nd, either guy could be the dad, though it would have been much more difficult for the first one to be the dad than the second, since he wore protection and didn't ejaculate. You would have had to be exposed to his pre-ejaculatory fluid (before he put on the condom, or on the outside of the condom) and the fluid would need to have had sperm in it from a prior ejaculation some time before the sex with you. Too bad it was drunken sex, to be able to remember enough about those specifics of the incident (that happened last July and you were drinking) you probably would have to have analyzed this closer to the time, and of course been sober. Have you considered getting a prenatal DNA test? It is expensive but then you would know. Ravgen and the DDC have reliable prenatal tests that use a blood draw from the mom (her arm) and a swab from the possible dads.
Post back with what kind of tests, maybe we can figure this out and come up with a better answer.