I hope you have been reading the Healing Library. It is very helpful.
Your emotions are going to be all over the place. How is your WH behaving? Is he NC with the OW? Is he completely transparent with you? Is he patiently answering your questions?
You know, you can go to Planned Parenthood and get all your screening done if you are too embarrassed to see your regular OB/GYn.
Trust me, they see EVERYTHING there, they know all the tests to run. Then, if you do test positive for anything treatable, they can prescribe the medication. You can take the lab results for anything more "permanent" to your regular doctor.
Your WH needs to go in and be tested too.