You left out the most-used method of all of time: Lactational Amenorrhea. Our foremothers practiced very different breastfeeding patterns, and babies were naturally spaced several years apart. Obviously, this didn’t result in no births, but it did result in few births. Those families a few generations ago with a dozen kids came about because breastfeeding patterns were changing. If the baby is given pacifiers and bottles and is sleeping away from mom, fertility returns quickly. Older nursing patterns mean extended time without a period, and thus no new baby for a few years. Even doctors tend not to know this. I showed up for a checkup when my youngest was a toddler, and was asked when my last period was. I counted back to nine months before my son was born — so a month about three years before. They were flummoxed and I had to explain the whole thing to them. Our early ancestors nursed for around six years!