Hello and welcome HCM!
To try to resolve your problems, lets do some maths. You said that your last period was around 25-28 May, lets say it began by 26 of May. And the next period should have come around 27 June. Therefore your cycle is about 31 days. Therefore the ovulation occurred in the middle of the cycle, that is on day 15-16 (which is 10-11 June). To be sure of not getting pregnant you should not have unprotected sex 3 days prior and 3 days after your mid period, that would lead to the more dangerous period between 13-19 June when there is a high chance to get pregnant if unprotected sex. With your ex you had sex on 10 June but he pulled out. Even though withdrawal is not the best method, the chances of remaining pregnant from your ex are tiny, even though when having sex sometimes small amunt of prostatic fluid are discharged unvoluntarily from the penis and it can contain small numbers of spermatosoids that can lead to a
pregnancy. However, it is little probable for you to have remained pregnant by your ex because you had sex like one week before mid period time and he pulled put, so little if no sperm was present. But the pregnancy cannot be ruled out!
Now, with the other gay you had sex on 19 and 22 June. In this case there is a higher chance of getting pregnant because the guy came into you, but however the sex occurred outside the dangerous window. If the ovulation was postponed then this would be a problem and there is also a chance of remaining pregnant.
The first pregnancy tested positive. Assuming pregnancy test are 70-99% accurate, then there is a high risk of pregnancy. Please repeat the pregnancy test!
Please remember that this math is valid only assuming that your cycle lasts 31 days and the ovulation occurs in the middle of it. Otherwise, the calculation have to be redone. If your cycle would, lets say 24 days, than this changes everything and the risk to have remained pregnant would be really high.
From this information it is impossible to determine who is the father as both guys could be the one who fertilized your eggs!
Hope it helps! Best!