When Do You Let Your Wife Know She's Showing?

Ok, so here's the question of the day:  when is the best time to let your wife know that she's showing?  I have thought about this question for some time and really couldn't come up with a good answer.  If I notice first and I tell her, what happens if it's just my eyes playing tricks on me and she's really not?  Boy, that would not go over well.  Then there's the other option that she could see it first and then ask me if I think she's showing... now I don't know about you but that seems like a no-win situation to me.  If I say yes then she would be upset because I should have noticed sooner and now everyone might know because her clothes were too snug.  Or, I could say no in which case she would know I was lying and again that wouldn't go well.  So, I kinda just hoped the whole thing would magically work itself out on its own.  I actually noticed a few days ago that she definitely had a little baby bump.  I watched as she was walking around getting ready for work in the morning and no matter what angle I looked at there was definitely a bump there.  I chose to say nothing (again in hopes that it would work itself out) but a few days later we went clothes shopping to get her some stuff for the coming months.  Well, apparently one of the shirts emphasized her tummy area and she came out with this sad face asking if she was showing.  I think my heart stopped.  I really didn't want to hurt her feelings, but there's no way I could fib my way out of this one...she can spot me lying a mile away.  So after my heart started beating again I figured I'd just go with honesty.  I let her know that yes she was showing, and I had actually known a few days ago but didn't want to say anything.  Of course she said I should have told her and she wondered if she was wearing clothes that were too snug to work.  Now she was worried that everyone knew (that response I at least saw coming).  But, as she always does, she didn't hold it against me very long and I was able to smooth it over with her with a little ice cream from Friendly's.  However McDonald's is on my bad list because we went there first looking for some magical strawberry sundae that I must have eaten with her like 10 years ago (I have no memory of it).  Apparently McDonald's changes their menu every so often so the lady behind the counter was clueless.  Thankfully Amy asked me to check around Glastonbury for a Friendly's (after I convinced her that other places might sell soft serve vanilla ice cream with strawberries) and I remembered that there was one like 3 minutes from our place.  There's nothing like seeing my beautiful pregnant wife happy as a clam with her vanilla ice cream with strawberries.