Low supply while on period?

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What do y'all do to correct this problem? I already add ground flax seed to my protein shakes and have been drinking water all day. I just started dieting again, but have been eating the appropriate amount of calories as far as I know. It's my first natural period since giving birth and it's heavy. I breastfed my son, he ate two jars of baby food and still wanted more milk. 😔 I may be worried over nothing but I don't know for sure.