The perfect time to do this is when you're in bed with the lights out and are casually chatting about the day.
We'd been talking about a friend who had just had a baby after struggling for years with infertility and it reminded us with our own infertility struggle.
Hubby: "look at us now though."
Me: "yes, married 10 years, 3 kids and... one on the way" *held breath*
Hubby: head pops up "WHAT!"
okay.. I laughed hysterically for like 15 minutes. He did not think it was so amusing. It still makes me giggle to think of it.
Prior to the above, between #2 and #3 baby, I had got him by setting out one of my positive pregnancy tests from J or E (I took like 50 just to make sure it was positive *L*) on the bathroom counter and wait for him to find it.
Then, of course, the joke was on me because I really did end up getting pregnant with baby #3, it went something like this....
@#!$!##!#$#@@#$!@#$##!! "omgoodness.. I'm pregnant." WAAAAAAAAAAAAAAAAAH... can you freaking believe it... wWAAAAAAAAh. Hubby thought it was a joke.
Poor O, I was upset because J was only 8 mths old and was still getting me up something like 5 x a night. Turns out I didn't have enough milk for her. Shortly after I found out she started sleeping through the night so I was getting more sleep. Turns out that my previous inability to get pregnant without hormonal support was no longer a problem. I hadn't even gotten a period yet and I got pregnant. So ladies be warned. :)
Course I wouldn't give O up for anything in the world now.