Two weeks ago I (male) had an unprotected sex, vaginal and oral with a long term female acquaintance. We had sex three times over the period of an evening and morning. My friend has told me she was clean and I myself had only ever recieved unprotected oral from a couple of encounters prior to this event. 

 I've had some anxiety post the event so I decided to purchase a at home STI test from a company called gettested which seems to be a Swedish company, operating in the UK. It was a 3-1 test for Chlamydia, Trichomonas and Gonorrhoea. I did the test and after 15 minutes the Chlamydia & Trichomonas where completely clear but on the Gonorrhoea part you could argue it has the faintest line possible, incredibly faint, you sort of had to be looking for it. I've ordered another test as thats what it has suggested because it was so faint it the card in the pack said another test would be needed. This has caused further anxiety. 

It has been 14 days since the event. I have no symptoms, I feel healthy and I guess my question is, are these tests accurate, and considering I have no symptoms is it likely I have contracted something?

Thanks in advance.