How likely is becoming pregnant while breastfeeding
It's quite likely you can become pregnant while breastfeeding that's why most doctors advise using birth control if you do not want to become pregnant soon after giving birth.
Most of our children are two years apart. In part, I contribute that to breastfeeding and the extended amenorrhea (absence of period) I experienced with most of my children while nursing. Our losses also contributed to more space between a couple of our children.