Does health insurance keep track of perscriptions filled and inform the policy holder?

my whole family is listed under the same health insurance policy so Im covered. however, I dont really want the policy holder to know what perscription I bought (its not dangerous just birth control and my dad was against it) so would it show on a bill or something? $50 is a tad expensive

Your drug purchases are tracked at the insurance company and at the pharmacy, but the policy holder ( your dad ) can only get a list of the drugs if he asks for it at the pharmacy. That would be his drug purchase. He would have to request every member's specific drugs and would probably be refused by the pharmacy (HIPPA law)
You can always go to Planned Parenthood and get your birth control pills there for much less money.

They don't usually send out information on the exact perscriptions that were paid for, but if he wants to find out and he is the primary policy holder he could find out easily enough.

If asks you about it just say the dr. perscribed them for you because you were having problems with your period - I doubt he will press further.
Generally they will not send a list of prescriptions filled, but that is my insurance company.