all they do during a physical is take your blood pressure, test your eyesight, weigh you, measure your hight, and listen to your heart and lungs, nothing personal involved. dont worry, its easy.
How do you suppose they will check for virginity? Maybe a finger test? Since you are a minor your mother is privy to any information regarding your health.
You're in highschool and you spell like that? I hope you're ESL. At a school physical I think they'll only take blood pressure and listen to your heart beat. A couple other things. It's no big deal. They won't make you get naked. They don't even do that at the doctors all the time.