I've been taking magnesium (Magnesium OK which includes B vitamins too) for about 3-4 months now for period-related headaches and mood swings. My mood swings seem better but I've noticed my breasts have become very tender, starting as soon as I ovulate. They improve at the start of my period. After my headaches seemed to improve last month they were back with a vengeance, and I also had a slow start to my period with about 4 days spotting to begin with (I've read this can be a sign of progesterone dropping off too early in the cycle - a shorter luteal phase).
The things in pondering are: is the breast pain linked to the magnesium? Might magnesium cause a shorter luteal phase? Does this sound like a low progesterone issue?