Don't beat yourself up for falling off the wagon; it happens. GWilson is right, just dust yourself off and hop right back on. Consider it a learning experience and move on. Going back to Induction level would indeed be a good idea, and drink lots of water to help flush the excess carbs out of your system.

Your doctor is a bit misguided for suggesting to go off low-carb. Eating more carbs, and less meat ... and then taking a pill ... doesn't make sense. It's true that whole grains contain some iron, as well as beans and lentils as Andy pointed out ... but it is present in these foods in a very difficult to digest and absorb form.

Actually, I just re-read your post, and if you're planning to donate your own blood pre-op ... then the blood service where you donate will check your hemoglobin level, and will let you know if you're low.

Doreen