I need advice about school

So I skipped a class and when you leave school you need a leave pass but I didn't have one and someone told on me. I don't have my teacher until another 2 Days and she's an absolute bitch. I've already gotten in trouble for skipping class and can't get no trouble. I need an excuse and I can't say I went to sick bay bc they would have it recorded and I would've had to ask her before I left. So what else could I say? I really can't get in trouble again 😁