I believe that dark, leafy greens *are* high in iron, but can also be high in calcium which counteracts it a bit (in an iron vs calcium fight, calcium wins). But if the salad made you feel happy, I say, eat more salads!
You might consider taking a prenatal vitamin if you're not already. I find I generally feel better when I take mine.
Another thing you should watch out for with iron deficiency is what people often call, "pregnant brain"--can't think straight, remember simple things (like where your keys are or even how to get home!). I had this problem until my dd turned 2 and I got pregnant and started taking prenatals again.