I feel like a horrible mother already!

I'm 17 weeks pregnant with my second child and I haven't wanted to take any belly pictures and haven't really felt the need to post every little thing on facebook or anywhere. I had a early scan at 15 weeks and found our we are have a girl but I still haven't told very many people! It's making me feel horrible because I see so many people posting pictures of the belly and ultrasounds and talking about every little thing they feel. Is it normal to feel this way?