I was planning to only breast feed and not use bottles or formula at all. I wasn't going to buy any bottles but my mum said even if I don't use them, it's a good idea to have some on hand JIC. I'm glad I took her advice. When DD was 6 weeks old me & DH wanted to go to a friends engagement party without DD. Friends of ours babysat and we sent DD with bottles and formula. It was also great when I needed a break coz DH could feed her. She was breast fed about 99% of the time until she was about 4.5 months and started full time daycare because I went back to work.