What would I have against a girl who was raped that I’d need to keep her away from my daughter?
A girl isn’t going to get secretly pregnant and sell pregnancy to other children. Nor is pregnancy illegal.
I can’t see how pregnancy testing would be useful.
Drug testing could be useful. A teacher may know but there’s a difference between a very strong suspicion and concrete evidence of drug use. These identified can be helped.
A kid on drugs is a kid with a problem that affects the other children in the school who are not on drugs in a negative manner. If my daughter had a drug problem, I would not expect them to allow the education of everybody else to suffer because of her.
As her father, I would want to know that my daughter was doing drugs in school, or had tested positive for drugs.