If you forget to take a birth control pill, take it as soon as you remember. If you don't remember until the next day, go ahead and take 2 pills that day. If you forget to take your pills for 2 days, take 2 pills the day you remember and 2 pills the next day. You will then be back on schedule. If you miss more than 2 birth control pills, call your health care provider for instructions. Those instructions may be to take one pill daily until Sunday and then start a new pack or to discard the rest of the pill pack and start over with a new pack that same day.
Any time you forget to take a pill, you must use another form of birth control until you finish the pill pack. When you forget to take a birth control pill, you increase the chance of releasing an egg from your ovary. However, if you forget to take any of the last 7 out of the 28 day pills you will not raise your chance of pregnancy since these pills contain only inactive ingredients. If you miss your period and have forgotten to take one or more pills, get a pregnancy test. If you miss two periods while taking the cyclic birth control pills (those that have the "inactive" pills at the end of the pill pack) even though you have taken all your pills on schedule, you should get a pregnancy test.
Source & Picture: www.webmd.com