I'm so bothered by my mil

An
Thankfully we don't see her often, but when we do (or when my husband talks to her on the phone) she asks every time if we are pregnant yet! I just find this to be so rude.
We are pregnant( 4 weeks)- but not ready to tell. The 10 months of trying and not being pregnant were long, emotionally devestating and very stressful. Her questions and comments felt like a stab in the stomach. I can't believe she didn't pick up on my reactions!
I wanted him to call and tell her we were as an April fools joke...hoping she'd learn to stop asking, but he wouldn't. He actually sees nothing wrong with her behavior! 
Anyone else go through this?!?