This is something you should talk with your doctor about directly. At 16, you are still a minor. Your parents still have responsibility for you.
One other suggestion, may be to contact your school counselor or a counselor at the hospital and ask this question to them. I gather that they must have dealt with this situation a number of times. Good luck.
This is a very complicated situation. You are still a minor and under the care of your parents or custodian.. However, being over the age of 14, you have certain rights protected under HIPPA. Speak with a Social Worker at the hospital regarding this issue and he or she could providenyou with more insight.
I will assume you want biodad to attend. He may have rights to attend in his own right. He should talk to the doctors. But to your question your mom has a responsibility to keep anyone away that attempts sexual relations with you since you are a minor. She might be able to have him arrested.