Ive always had irregular periods, and for the past 3-4 years Ive had 2 periods a month, one would be heavy and long, the other would last 4 days and be extremely light. (usually)
Ive been on Loestrin FE birth control for 6 months now to try and regulate, and it has helped. A lot. No more cramps, no more heavy periods, and the best part, one period a month. This is actually the first month that Ive only had one period, it takes awhile for your body to get used to the medicine. But its a suggestion for all the girls who have irregular periods, Ive had good luck with it so far. The first 3-4 months I was extremely emotional though, and lost any sex drive at all, only bad side effect Ive had, and the sexual drive is coming back now. But now its SUPER light (Im actually thinking of getting a Diva-Cup, because its so light that my light tampons wont get wet enough during the day and they hurt to take out) and they only last 4-5 days.
And I dont know about the iron thing, but I know that these pills do have iron in them on the days you are suppose to be on your period to supliment for all the blood and iron you're losing.