Which date?

My boyfriend and I broke up for a bit. I slept with someone else March 9th. We got back together March 11th. I just found out on the 2nd that I’m pregnant. I never thought I would be in this situation, but here I am. What are the possibilities it’s my boyfriends baby and not the other guy? The 9th is the only time I slept with someone else

Edit - my boyfriend knows. i told him about the other guy as soon as we got back together. he’s aware of the possibility. i havent had my appointment yet, it’s scheduled for tuesday.

i don’t know if the other dude came. i don’t remember the night, i can’t recall anything after we drank.

i took a test the 25th and it was still negative if that makes any difference.