I decided to get checked out because it had been a while since I last did.
Went 5 weeks ago and gave blood, urine and oral swab sample. You may have to be (semi) honest about your activities if you want all three depending on your local GUM's policies. I wasn't honest and they were a bit surprised I wanted all 3 when I had only disclosed one casual sex episode with an EE girl where I had used a condom, had OWO and done RO, but they did the tests all the same.
2 weeks later I got a text back to say "please ring for an appointment" which worried the shit out of me, particularly since I only picked up the message late Friday and they weren't open until the following Monday. Rang back Monday, only to discover they had lost my urine sample! Revisited the day after, where they were able to give me the all clear on the blood and oral swab tests, but I had to re-provide a urine sample. Had to chase them today as no text after 3 weeks, but glad to say all clear.