I exclusively breastfed to 6 months - and beyond mainly because I had no issues, pain (beyond first few days) or need to return immediately to work and it was easier than faffing with bottles and sterilising. If any of these factors had affected me I would have had no qualms (or minimal ones) swapping to formula. There can be no judgement in how you choose to feed your children - the people I judge are those who don't bother with their children not those who agonise over every decision. I think, in the main, if you love your children and want to do your best for them - then that's good enough!