Well I know what it is and having been caught and embaressed I decided to move out. But your daughter is still young being that she's in school. So tell her you understand she's having sex and that you would prefer she not do it under your nose, in your home, whatever you feel you need to say.

My now 18 year old daughter just started birth control, so that she doesn't get pregnant when she stops abstaining from sex. I'm happy for her decision and openess. I got pregnant at 20 it didn't go well and i wasn't on birth control. My parent's were less open about such topics but my mom did throw birth control at me when she found out i was having sex just didn't take it. Anyway get your daughter on birth control, thinking they will never have sex is an illusion plan and protect.