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If you have been on birth control for over a month then you are protected against pregnancy.
If you've been on the pill a month and haven't missed any pills then you're protected against pregnancy.
There is a 2% chance pregnancy will occur as you were not protected against pregnancy during the time you had intercourse and unfortunately you are still currently not protected against pregnancy. Because of this you need to use a backup method of protection, a condom, for the next 2 weeks to prevent pregnancy. Continue taking birth control as normal (one every day).
This is what you would expect to occur; but there are slight chances to become pregnant even when taking the pill.
If you take the BCP everyday as directed you are 99.5% protected from pregnancy.
Birth control is not a 100% way to stop pregnancy and your period makes those chances even worse.
If you've been on birth control for over a month then you will be protected against pregnancy.
You will remain protected from pregnancy even through your placebo week, if you take your active birth control pills everyday at the same time(including being on birth control for 2 months.In other words, if you take your birth control everyday at the same time, you will consistently be protected from pregnancy.
Of 100 couples who stopped the birth control pill, 85 will experience a pregnancy within one year if they don't start using another method of pregnancy prevention.
Females who are sexually active, want to be protected from pregnancy, or would like to regulate there menstrual cycle, should use birth control.
Get on birth control if you're still worried about chances of getting pregnant use condoms while using birth control also.
If you're on the birth control pill and had a negative pregnancy test, it is not likely you are pregnant.