I don't really remember how much I drank, but I'd say about 10-15 shots of crown and a shot of 151 rum. And I didn't eat the whole day, but I puked the same night for 2 hours. I drank on a Monday, and I go in to see my p.o on Thursday. If she tests me for urine or breathalyzes me, will I pass? And I'm under the age of 21.

Yeah you should pass. I don't know why your po would use a breathalyzer... She's probably going to do a UA which you should pass. It takes about 24 hours to 48 hours for alcohol to leave the system. Just drink a lot of fluids to help. Also, stop drinking. Or violation probation for that matter. You're lucky to not be in jail and unless you want to be in jail or don't care, continue violating because probation is no joke. They can surprise you whenever they want to.