Given your large family I will take your word for the latter ... but to be honest, I can't see how you can "experience regular pregnancies" without having a period. Are you suggesting that those regular pregnancies can be timed and planned to occur exactly on your first post-breastfeeding ovulation?
It’s not unusual for women who have a healthy reproductive system and regular marital relations to conceive on the first ovulation after childbirth. This can happen they’re breastfeeding and ovulate two years later, and within weeks of delivery, if they don’t breastfeed.