I've been having my 7yr old niece over to play with my boys a couple times a week for the Summer.  During one of her last visits she asked "Aunt Debbie, how did you get pregnant?"  I told her that was a question that she really should ask her mommy.  I really didn't feel it was my place to field that one!  Of course Alex, my 9yr old, chimes in "It has to do with eggs and sperm."  I told him that was really as far as the conversation should go.

Today I took my boys shopping for school supplies since I am due to give birth any time and figured it would be easier to do before the baby came.  I had to go to the bathroom while at the store, of course, so I took the boys in the restroom with me.  While in the stall my 6yr old was testing out all of the sinks and my 9yr old apparently took interest in the vending machine.  He asked "Mommy, what's a tampon?"  Good grief!  What do I say about that?  I responded "That's something only ladies need so you don't really need to know."  Luckily he was satisfied with that.  Then, after a bit of a pause, he asks "Why would anyone need to buy a napkin in the bathroom when there's paper towels and toilet paper?"  Trying not to burst out laughing, I responded "It's a different kind of napkin and again, something only ladies need to use."

I don't know how child psychology experts would have handled that but I think telling my daughter about those things will be difficult enough.  I don't see the need to get into it with my 9yr old son.  I'm sure he'll know about those things when/if he needs to.  I've already been asked if sperms and pee can come out of your penis at the same time.  It was so much easier before they were thinking about these things!