i think drunk me did something bad

ok so my SO and i were out at a bar drinking...well we ran into one of his friends from high school...well the night goes on we all get drunk and we end up going back to his friends house to sleep, we woke up the next day and he had to work...so he took the car home and i stayed with his high school buddy...we were all still a lil drunk from the night before and his buddy and i immediately jumped back into drinking again...well we went to a pool part drank some more and at this point im drunk enough that i dont really know whats going on very much but i still kinda remember but im kinda pretty sure his friend had sex with me when i was trying to sleep....i ignored it for a week but brief memories keep coming back and idk what to do EDIT**** ok so a question was asked of why i didnt leave with my SO...well that is because he was almost late for work and didnt have time to drop me off at home and still make it in time....and we werent getting drunk alone it was at a pool party with other people then when everyone left i went to take a nap because i was obviously intoxicated and needed to sleep....i never inteded to call out the rape card...i know im at fault for letting myself get to the point where i couldnt defend myself or even properly say no...i did ask his friend and all he had to say was not to tell his fiance (ugh) and he would never say anything to my SO....im disgusted that i let something like that happen but it wasnt intentional and i believed i could trust him because he was friends with my boyfriend...thats not a mistake ill ever make with anybody ever again...i dont know if i want to tell my SO because he is a very protective man and id hate to hurt him or make him feel guilty for leaving me there....also im not some college kid im 24 with a four year old and my so is 31, it was just our day off of work and my son was with his dad so we went a little overboard trying to enjoy our freedom