In theory, if you have been taking your active pills properly, you should not get pregnant during your placebo pills. The pill essentialy stops you from releasing an egg. As such, if no egg was released, you should not be able to get pregnant during your period. However, that's only if you took the pill as directed.
It is possible to "skip" menstruation by not taking the placebo birth control pills and instead starting a new pack.
By skipping the placebo week, you only lower the risk of accidental pregnancy. It's possible to get pregnant using the birth control pill, but taking the packs back to back doesn't increase the risk.
Skipping your period by taking extra birth control pills or fewer placebo (sugar) pills lowers, not raises, your risk of pregnancy.
A placebo has no medical properties at all so, yes, you would be at risk of getting pregnant.
If you took the active BCP as directed you do not have to worry about pregnancy during the week of placebo pills.
Changing birth control pills doesn't increase your risk of pregnancy if you started the new pack on time. It is possible to get pregnant even while using the birth control pill correctly, however, so take a pregnancy test if you're having symptoms of pregnancy.
A placebo effect
No, the placebo pills are exactly that, placebo. (just sugar pills). It would be like expecting a tic tac to bring on your menstrual cycle. If you are on the pill, the placebo pills will start your cycle because they have no active ingredients. If you think you are pregnant and want your period to come, go to a doctor/do a pregnancy test or take the morning after pill if it's not too late.
Yes. The birth control pill does not work perfectly, and it's possible to get pregnant even when using it perfectly. However, being five days into the placebo pills and not getting a period doesn't necessarily mean you're pregnant. As long as you followed the program all the other days of the month you should be fine. The sugar pills are just to help you keep on track with your habit of taking the pills.
Different birth control pills use different colors for active and placebo pills. Your question can't be answered without knowing which pill you're taking.
Missing a placebo pill does not affect the chances of pregnancy.