Is 28mg of iron too much? I feel like that's too much, I'm taking a prenatal that has a lot more…

Is 28mg of iron too much? I feel like that's too much, I'm taking a prenatal that has a lot more than our daily intake and TMI but idk if it's that but something in the prenatal has been making my stool a green(sometimes bright green) color and I wasn't sure if that was normal too, never happened with any other prenatal I've taken.