I'm going to take a nerd approach here...assuming that the birth control pill when used as directed is 97% effective and a condom when used entirely correct is 96% effective then here's what we have: A 3% chance of pregnancy with the pill and a 4% chance with a condom. Now when used in conjunction with one another we have the probability of A intersection with B (A = pill, B = condom) since these two events are independent of one another. Therefore to determine the likelihood of event A or B happening or both events occurring we would simply multiply P(A) X P(B), yielding 0.0012 or 0.12% chance of pregnancy given both are used correctly, as directed, and in conjunction with one another. So, if you have sex using the aforementioned method with no pregnancies 832 times...I'd be careful about one more night of passion b/c the law of probability says that girl is gonna get prego!! Hope this helps and makes it a little easier to understand.