I get these too, all well written. I think you're right.
I think this may also be hoax spam for his wank bank. You never met him, so no previous. On top of that it's an extended booking and he's wiggling extra juicy bait in front of your nose. He happens to be in the medical field too, that's convenient. Classic set up. Plus there are professional BB providers for less ££ or
free on AW so why you? I don't believe any of his script, who he is or anything about tests...he's sipping mojitos on fantasy island.
All the tests show is X was clear for the past 1-3 weeks before they got tested. As some STDS have a 1-3 week incubation period.
Tests won't show that a person is incubating an infection caught the night before they rolled up at the clinic for example.
If he BB with folk straight after the test and they have HIV, hepatitis, clam, syph, gono or herpes that will not be a nice goodby present for you. Unless you're on anti HIV meds,which doesn't prevent the other infections. If you look around AW you'll see the similarity to other proposals. Personally I'd ignore.
It's you're choice, it smells of con, despite his positive FB, which is often purposely misleading or favour swapping.
Nothing stops you investigating how genuine he is...fuck with his head and request a deposit of £500 today