The Woes of Trying to Conceive

Today, I found a new pet peeve. I'm sure every woman that has tried to have a child has had the same one. A girl at work asked me if my husband and I were planning on children eventually. I told her that we were trying for one now. She gave me a dumbstruck look and said, "You mean you have to try? I got pregnant the first time." I nodded and smiled, but inside, I was fuming. Why is it that women that don't want a child get pregnant so easily?