I would say, "definitely get the school nurse or a teacher you feel comfortable with to help you talk to your parents" except this is the weekend, and I hate to see you wait any longer at all. What if you just told them you had soemthing hard to talk to them about? Or do you have an aunt or grandma that you could call right now? and have them come over?
Please don't wait any longer-your parents need to know right now so they can get you the right help! Don't overthink it-just do it.