Fertility & Hormonal Birth Control: Impact on Egg Supply & Cancer Risk

Question
I am a 28-year-old woman, no kids, and married for 10 years.  We have practiced rhythm and barrier methods, since I had a personal aversion to hormonal contraception.  However, I've developed a few concerns recently: since women are born with a set nunber of eggs, am I actually depleting my supply by refusing to take BC that interrupts my period?  Am I leaving myself at risk for cancers by allowing myself to "bleed" unabated for years?  We're planning to get pregnant in the next 3-4 years, but I'd like to hold on to what I've got until then!  

Answer
Not being on the pill has not harmed your ability to become pregnant. But you should be aware that the 20's are the time of highest fertility for women - the time when those that are able to become pregnant have the greatest success. Fertility begins to decline in the late 20's. If you think you eventually want children, you many want to consider the age issue. Never having been pregnant increases the risk for uterine cancer.