Once again, that doesn't... make love an immoral or otherwise bad act? It's designed for impregnation but you and I both know it's much more than that. Besides, there are things out there designed to stop pregnancy. I don't see why the girl should be blamed if the condom breaks or the pills mess up, or anything else that could possibly happen.
And even if she willingly had unprotected love, that's her right, and the school does not have a right to deny her education based upon that, nor does it have a right to deny her education should she not willingly submit to an illegal and invasive medical test.
Also, you know, love has numerous long-term positive impacts that benefit society in many ways: one of them being people.