How long does it take for birth control to prevent pregnancy?

Like if my boyfriend c u m s in me..How long does it take for birth control to prevent pregnancy?
When starting birth control pills, it will usually take 7 days for the pill to become effective at preventing pregnancy. You will need to use a backup/second method of contraception during these 7 days (such as condoms). Keep in mind that birth control pills offer no protection from acquiring STI's/STD鈥檚.





Be aware that your first and last active pills are the most important pills in your pack. Being late starting your next pack or forgetting your last active pill will lengthen the time off the active pills. Lengthening this pill-free interval can allow your body to ovulate. Try to plan carefully when you need to start or purchase your next pack. Remember your pills when you go away for weekends or vacations.





To help you remember to take your pill every day, it is useful to link taking your pill with some daily activity like brushing your teeth or eating a certain meal. Some women set a watch/mobile alarm to go off as a reminder. Each morning check your pack to make sure you took yesterday's pill.





If you have any concerns or further questions, I recommend you discuss them with your doctor to see what he/she says.





Good luck :)How long does it take for birth control to prevent pregnancy?
I just started Yaz on Monday! My doctor told me after 7 days It should be effective (95%), I cant wait haha. I really hope its effective, I thought about maybe getting spermicide or something just to be extra safe, but I def. Dont want to use condoms anymore. Im married, so i really dont have to worry about diseases, so hopefully you and your b/f are faithful :). It seems like it should take longer than 7 days, Im a bit nervous to go the whole way the whole time, but my doc sounded confident in it. :crosses fingers for the both of us!: lol
Condoms work immediately, so does Depo-Provera and a few other things. The Pill takes time to build up in your system. It all depends on what method you use.
The information pack that comes with the birth control will tell you to wait at least 7 days after starting the pill to have unprotected sex.
A condom is almost a sure preventative if used properly other types will vary depending on the type of bc.
Depends on the birth control.