Is it possible for birth control pills not to work?

and if so what are the kinds of side affects u feel before u know ur pregnant?

if taken correctly (every day) they should work. but if you forget to take one and then neglect to "double up" there is a chance of pregnancy.

symptoms of pregnancy: fatigue, moodyness, and eventually missed period. Source(s): ivillage.com, babyzone.com, discovery.com

It is very possible that the dosage is too low. You may need to have the doctor up your dosage. There can be many signs that you are pregnant. You may have nausea, tenderness of the breast, period is late or unusual. Good Luck.
It's not possible. BC pills are 100 percent infallible. Absolutely, completely incapable of failure.
Yes, it's possible. My best friend was on the pill AND used a condom and got pregnant.

Pregnancy symptoms are very similar to PMS symptoms - cramping, bloating, mood swings, etc. The only way to know for sure is to either get your period, or get a positive pregnancy test.
Taking antibiotics lessen the effectiveness of the pill. Some of the signs of pregnancy include breast tenderness, nausea, and frequent urination.
yes it is possible. If taken correctly the rate of failure is VERY slim. However, if you miss a pill(especially at the beginning of the cycle) the chances are significantly higher. Your breasts might be sore, you might feel more tired than usual, you also could feel nauseous. There are many other symptoms too. But you might not feel any symptoms at all before you find out you're pregnant.