What issues are important in determining how this situation should be managed?

A 14-year-old female presents to her primary care provider wanting to start “the pill”. She has been with her boyfriend for 8 months. They both agreed that they wanted to start a sexual relationship and have already had intercourse on two occasions where they did not use contraception. She had never been sexually active before. Her periods started 3 years ago and were initially irregular, but she now reports a regular 27 day cycle. She has never had any gynecological or other medical problems.
She reports that she is happy at school and she is one of three children, with a brother of 21 and sister of 19 years. She lives with her parents in a house locally. She has presented today with a friend from school.

Questions:
1- What issues are important in determining how this situation should be managed?
2- How would you further investigate (diagnostics), advise and manage this patient?