What's the max amount if magnesium and b2 a pregnant woman can have? want to up it for migraine ease. thanks

The usual dosing: The typical dose for the indication you describe is 400mg vitamin b2 or riboflavin and 500mg of magnesium. This is unlikely despite the high dose of vit b2 to have any toxicity as the body limits it's absorption, and the excretion of the excess is efficiently done through the kidneys. The vit b2 will turn your urine flourescent yellow, the magnesium, the stools a bit loose, but no worry for baby.