You should, as always, consider the implications of this. A setting where women reliably have mysterious but verifiable magical powers is also a setting where when you go raiding, you need to prioritize killing the women as quickly as possible, since they are likely to have magics you have not seen and cannot counter.
You'd presumably see a lot more war-to-the-knife low level conflicts, since stopping a rival tribe from being able to oppose you would necessitate also destroying their breeding population.
Or, of course, you can do it the other way around, and assume that women as a whole can actually muster enough magic to counter their opposite number's strength and aggression, but then you're building a setting in which magic is a force used as commonly and reliably as physical strength is in our world. Which would be really interesting to read if someone tried to set it up, but also would be by necessity divorced from its mythological roots.