What can I do to not get sick when I take iron?

I am 28 weeks pregnant and my Dr. office called and told me I am anemic and that I am to take a prescription iron pill. I always get severe stomach cramps and vomiting when I take any kind of vitamin containing iron. The vomiting and stomach cramps when I take iron was happening before I was pregnant and even as a child so I know its not just pregnancy related. As a result of this my Dr. told me not to take prenatal vitamins and I have been doing fine up until now. The pill doesn't even stay down long enough to have a chance to have to even start to really do any good. Sorry if TMI. I also have been slightly anemic my entire life because of my other health conditions witch limit the amount of a lot of foods I can eat. I have IBS-D and my GI Dr. has told me I am to not eat anything that causes "gas" in the intestines. So that eliminates Broccoli (I love broccoli) and any green leafy vegetable. I also have to severely limit how much red meat I eat as it causes me pain to digest. I also have Fibromyalgia and Symphysis Pubis Dysfunction (SPD) and GERD. The fibromyalgia aggravates everything else causing the symptoms I feel to be more pronounced. (thought I would give a little more background on my situation if it helps at all).I was just wondering if anyone else has this issue and what if anything I can do to take the iron pill with out the "side effects"