Medical trauma from rape kit and 2 night hospital stay 14 yrs ago is resurfacing now during miscarriage f/u exams. How do I approach my ob about this?

Simply tell him/her. I'm sorry for your loss -- & suggest simply telling your OB doctor what you're experiencing. Most doctors have compassion, and want to keep patients as comfortable as possible. They can work slowly and be gentle, so that necessary exams can be done without further suffering. It's also possible that working with a good therapist can help with your feelings about the earlier rape as well.