Just planning on what I can do safely, as I would hate to get an STI, so more concerned than fixated!
There is no guarantee you will be safe. After all even with full protection Herpes can still be passed on as can genital warts. If she has chlamydia or Gonoreahh in her mouth/throat then even kissing can be risky.
If you are really worried about the risk then it is better to stay at home and have a wank. After all even if the girl say she was tested last week and was all clear you only have her word for it. Also if she is going to be licking and sucking your balls remember saliva spreads around very easily so very likely to get on your cock as well. If you are so worried and only want OW then avoid this
I wish I could say don't worry we
all get checked regularly but I cant as I know it is untrue and know a few that have never been near a GUM clinic. A few years ago I worked with a woman for a year and a half who has mixed reviews on here who didn't even know where one was let alone visit