Called Planned Parenthood and ask for a midwife or a nurse-practitioner. Or, find a local midwifery clinic or a clinic that employs a mix (midwives/NP's/doctors).

The reason: midwives and nurse practitioners are lower than doctors on both the educational and salary ladder, so, more "equal" to you. Less of an "authority" figure - since your mom and abuser are both, on some level, an "authority", you need to lessen the "authority" aspect of visiting a woman healthcare provider.

Plus, Planned Parenthood's clinicians are more used to young adult clientele, so they should be able to connect with you and assuage your fears.

My recommendation is to briefly inform the clinician you will see about the abused-by-a-doctor part of your history, so that the clinician knows to be extra gentle with you. If you cannot say it out loud, write it down in a note and give to the clinician in the beginning of your visit.