My daughter was born December 2014. I exclusively breast fed but by 8 weeks was exclusively expressing the breast milk due to problems she had feeding from me due to chronic thrush. I was expressing over 1000ml a day but my periods came back at 4 months ish, had my first period, 34 days later my next period and I got pregnant that cycle (we also want a fairly big family and didn't want to wait). When I got my periods back the week before my period and the week of my period my milk supply drastically lowered and nothing I did improved it so I had to rely on freezer store of expressed milk to make up the shortfall. However once I feel pregnant my milk supply almost instantly dried up, there is nothing you can do if that happens, pumping extra doesn't work or anything like that, it's just hormonal. I carried on trying to get what I could out (maybe 300ml a day) until 7 and a half months when I switched her (reluctantly) to formula. I had started weaning her at 4 months but she didn't drop any feeds until about 6 months so was having just as much. By the time I stopped she was only having about 500ml a day. She has always been healthy and loves her food and on the 75th percentile on growth chart so no adverse effects. I'm due next month and hopefully this one will feed more easily from me! X