yep, my iron stores deplete quickly too during pg. I had fine results early on but at my last blood test they were getting really low. And I was still taking my vitamins! I'm on iron now, and they are still a little low, but nothing to worry about too much. It take a while for my stores to build back up. I was on iron for a yr after PPH. And for 6mths after giving birth. I think it depends on your own make up. I hope you're feeling better soon! There's nothing worse than the tiredness of low iron stores!