I had a partial thyroidectomy last year, I was still breastfeeding DD2 who was just under 2. Understandably my neck was quite sore but I was able to breastfeed her 24 after the procedure after the strong painkillers were mostly out of my system, the Anethestist (sp) say he normally recommends 48 hours but dd2 was having such horrible teething at the time that a bit of added help from me wasnt going to cause her long term harm. I was in hospital for the night after the operation (had op at 5pm) and went home at lunch time the next day due to the separation anxiety my kids had/have as well. I had my mum stay for about week after the op to help with the girls without that help I would not have coped as I was achy and found it hard to turn my neck for about a week. When I had good movement in my neck I started driving again. I am not sure you would be able to breastfeed the day of your op depending on what pain relief you get. Find out from your surgeon what anaesthesist you will be having and ask the questions now.