Mum wants to tell friends

I had a bit of a disagreement with my mum today (I should point out I'm 33!) first pregnancy, 10 weeks. So I've told a few friends but only one to one, close friends who I would feel comfortable going to and saying if it all went wrong. Friends who I know can't/won't spread it to wider groups. Mum got seriously pissed that "I'm allowed to tell and she's not". She probably only wants to tell a couple of friends, I totally get her excitement at first grandchild and I want to share this experience with her. But I don't want her friends to know before first scan! I don't want them to discuss me or feel sorry for me if things didn't work out. I feel really protective of my body and my right to privacy. I would understand mum's upset if I'd announced to groups of friends, or spoken on social media but I haven't. Maybe it's pregnancy hormones but her saying "it's my news too" really got under my skin! Yes, but we're not physically sharing this pregnancy. I just want her to say she understands where I'm coming from, even if she disagrees but she actually said no, she couldnt do that.  Aaaargh! Am I being unfair?