Well, congratulations.
You’ll get some measure of revenge for this little joke of hers over the next nine months.
Everytime she runs yarking into the bathroom, or starts eating really bizarre things (Mrs. Dave-Guy was jonesing for relish sandwiches), or can’t hoist herself out of a chair, just chuckle a little and say, “You know, honey, I’m still laughing about how you made me think you were playing an April Fool’s joke on me with the pregnancy test.”
The best thing about this is that, at least in the last trimester, she won’t be able to chase you and catch you.