My friend has just discovered he's HIV+ and his doctor insisted that I went to the Red Cross just along from Chula Hospital to have a test myself.
It is under the water tower halfway between Sala Daeng and Ratchadamri skytrain stations.
What nice ,helpful and considerate people there.
Fill in a computer form, upstairs to pay 210 Baht, then the prick(!).
Result in one hour or by email.
Result negative.
Only had the test once before, scores of years ago,(to get a mortgage) and wait ten days for the result (think of the torment in the past waiting TEN DAYS).
The red Cross centre is part of the Chulalongkorn hospital but considerably cheaper.
Almost a pleasant experience.