I find I am very shy as a Mum and the conversation never got past talk about there child my child oh how cute stuff.
Even now at 3pm I am found standing on my own although I do smile and say hello to as mamy people as I can. Its the kind of village where everyone says hello though!
Do give it a go and stay as positive as possible, always be ready to say hello. If after a whle it doesn't feel right try somewhere else.
I actually look forward to taking my DD to her dancing as all the Mums sit in the coffee shop and chat. I decided on day one I was really going to try. I plonked myself at the table and just kept smiling and nodding while they chatted. It took a couple of weeks but I slowly joined in, we've even been on a night out. Never thought I'd see the day.
Maybe it's easier when their older if your not really into the baby chat.
Just keep , they will either start to chat or think your completly insane.