Keeping supply up on period

Unfortunately I've now had 3 and they appear to be regulating. Baby girl is 5.5 months, but my supply tanks hard on my period.

I've seen the recommendations for calcium and magnesium, but do you guys take that in addition to taking the prenatal? My Dr recommended to keep taking those and while I'm not as good at it as I was while pregnant, I'm trying to get better at that.