If you're uncomfortable and/or it is not convenient, don't go. Your friends will understand (and if they don't, it is not worth worrying about), but after all it is their day and it is an invitation - you're not compelled to attend. A few years ago, my now sister-in-law got married. Not that we would have wanted to, but there was no chance we could dodge this - I was an usher, Mrs Minton was a bridesmaid and the kids (the youngest of which was only seven months) were bridesmaids. It was a great wedding and we had a great time, but frankly if we'd had the option, we would have welcomed the break if we could have left the youngest - I missed almost all of the photos, we both missed various courses of the meal, we both missed the speeches, we both missed the first dance and we had to leave early. If you can, leave baby at home!