Condom & Withdrawal: Understanding Effectiveness and Safe Sex

Question
My boyfriend and I recently started having sex (we were both virgins.) I bought brand new condoms and they fit perfectly fine on him, even checking to make sure his foreskin could move easily so it wouldn't fall off. He pulled out too (with the condom on) a good amount of time before he actually came and afterwards, I checked to make sure there were no leaks or tears in the condom and there were none each time we did it. On the box it says the condoms are thin with extra lubricant from Durex. I read they are one of the best from recent condom studies. How effective is this method? I am really scared of pregnancy and I am taking all the precautions I can since I am not on birth control.

Answer
For the average couple using condoms, they are about 85% effective, meaning that in 1 year, about 15 couples out of 100 will get pregnant.  When used correctly every time, condoms are about 98% effective, meaning that only 2 couples out of 100 will be pregnant in 1 year.  So if you continue to be so careful in using condoms, chances of pregnancy are small.  If you want to get nearly 100% protection from pregnancy, the birth control pill will do it, as long as you never miss pills.