Hi Goober.
I suggest taking the iron supplement with a glass of Vit C fortified/enriched OJ as opposed to another supplement.
Vitamins and minerals are shown to be better absorbed through foods rather than supplements, so the less supplements the better IYKWIM.
Make sure you stay away from liver- it is really high in Vit A, which we are ment to avoid excessive amounts whilst pg.
There is way way more iron in red meats than green leafy veges, so stick to the red meats where ever possible.
Also, check out changing supplements- I know elevit is a complete pg and bf supplement that includes iron, although it is a bit more expensive.
Make sure you increase your fibre as iron supplements tend to make you more constipiated. I also suggest playing around with the time of day that you take the supplement. I know if I take mine in morning I am contispated during the day, but if I take it at night I am okay.

HTH
Blueflower