How long do you have to wait to have sex after antibiotics( birth control) ?

Don't have to wait: Despite what you will read on the internet, most commonly used antibiotics don't interfere with the effectiveness of birth control very much and you can continue to have intercourse normally while you are on them. Unless you are being treated for something unusual like TB, it is unlikely to make much difference. If you are worried, you should use a back-up method until you start a new pack.