There used to be natural methods of birth control, taken by men and/or women. Certain herbs would make the uterus too slippery to hold the fertilized egg, as one example. These modern methods are very harmful, the birth control shot being one of the worst for women.
There are certain times astrologically when conception should not happen, as it can cause aberrations to the fetus, which many pro-lifers ignore. Not everything is about your own personal karma. The Ancients who were knowledgeable, and us Zevists, need to make the best choices.
I'd say, time it at infertile times, and if it happens, it happens. Gods willed it.
We are not christians who say "God willed it". Adding an s to make it plural to sound Pagan doesn't cut it, it's still an christian belief. Conception happens at bad times as I mentioned above, and just because something happens doesn't mean it was the will of the Gods.