Other People's Kids While TTC

I love kids and worked as a nanny for years. My hubby and I had one miscarriage 3 years ago and have been ttc so far unsuccessfully ever since then. Lately I started noticing that other people's kids irritate the hell out of me. I mean I want to run away whenever a friend shows up for dinner with her child. That worries me. Anyone feeling the same way? What's your solution?