I was just wondering about how many of the girls in thailand that are using birth controll pills?

I had sex with a thai girl, i think i used the condom properly, but for some reason i have some doubts. So the question is: what is the chance that this girl took birth controll pills?

Completely impossible to say.

Use of birth control (of which pills are just one type) is very high among married Thai women, but presumably that is not who you were with.

Among unmarried women, some use, some do not. Women who are directly or indirectly in the sex trade often rely solely on condom use by their partner/clients.

BTW when something goes wrong in condom use (breaks, slips off etc) there is a widely available medication that if taken within 72 hours (preferrably within 24-48) will protect against pregnancy. Most Thai women/girls (especially the younger, unmarried ones) are well aware of it. So IF the woman you were with knew that something may have gone amiss with the condom she would probably have known what to do.

Needless to say the time to ask whether a partner is using contraception is before having sex, not after.

How can you have doubts that you used the condom improperly? Are there new fashionable ways to wear one? Fairly straight forward, and as far as screwing one up id be more worried about an STD.

Probably not enough as many Thai girls are worried about their skin going dark if they use the pill.