Thanks for your query.
Birth control pills if taken regularly are more than 95 % effective in preventing pregnancy
Also, emergency contraceptive
pills taken within 24 hours are also similarly highly effective.
However, in the first cycle of birth control pill use, it is common to prescribe added barrier method of contraception
, because it takes a month for the pills to start working, as they are hormone containing.
Still, the chances of your being pregnant are highly remote.
But they are not 0 %. There is always a theoretical risk of pregnancy, however negligible.
Wait for your next period, and go for a urine pregnancy test, if you miss your period.