Getting pregnant while breastfeeding
This is something I have done twice. It's not really something I felt I had any control over, more just sheer luck. When I conceived each of my girls, i was breastfeeding, but my supply was dropping/changing. I do not believe my body is capable of ovulating and breastfeeding at the same time, but the changes in supply were enough to make my body think I was stopping and re-start ovulation. With Audrey, Mason was in the process of weaning, and my supply was dropping. When Hayden was conceived, I had gone away for 4 days and didn't have Audrey with me breastfeeding. Although I was pumping, I wasn't getting as much output as I knew she was getting when I was home, so once again, I think my body got tricked into thinking she was weaning (I ended up nursing Audrey through my entire pregnancy with Hayden and even tandem nursed the girls!).
Some women get their cycle back within just a few weeks of having a baby even if they are breastfeeding. Others, like me - don't get it back for over a year (or even longer!). It's all about what your body can handle and what kind of cycle your body is on. If you are hoping to get pregnant, are breastfeeding, and haven't had your cycle return, I would suggest making small changes to your breastfeeding routine to see if you can get your cycle to restart.