The standard HIV test requires 1 month after sex, there is another one available after 15 days, I'll check for name in a minute (P24 Antigen test). Red Cross is a good place to go if near The Thai Red Cross AIDS Research Centre
02 251 6711
https://maps.app.goo.gl/QYFSMnaogEahoxmG7
BTW it's extremely unlikely you have HIV after one time, the odds are remote. Risk depends if anal, other person on antivirals or not etc