Minor rant about my mother

JCRSMD17

Grrr, found out today that my mother is gossiping about me to my MIL behind my back!!!!

I am 10 weeks today. DH and I have decided not to tell anyone about the pregnancy until after our Level 2 US at 20 weeks. So no one knows yet that I am pregnant and I am not showing. However apparently my mother became suspicious during a weekend visit and is now talking to family members. She told my MIL that she is SURE I am pregnant and wondering when we will announce it. I realize she is probably just excited about the possibility of another grandchild ...

But I am annoyed because as a FTM, I kind of feel like she's stealing my thunder. If all my family members suspect the pregnancy then the announcement is a little anti-climactic. What, if anything, can I say to her? I really really really don't want to confirm the pregnancy yet. Am I being totally irrational?