well since your highschool if huge as hell like mine, you should beable to just call in w/ a fake adult voice, it seriously wont matter, and just say "my son/daughter has <>insert LAME disease, they get suspicious if you say ebolla, diarhea,<> and wont be able to come to school at all today", thats what i do, they just say thnx and immediatly hang up, easy as shit, sorry if your parents stay home during the day tho, and fake puke has NEVER worked for me, just stick your finger down your throat until you puke, its actually not that painful, and microwaved towel on the forehead for a while b4 your parent wake up helps to, just make sure you get your face MILDLY DAMP, not wet, after the towel, otherwise it looks suspicious too, folow those rules, you should be fine