M.,
Awesome question and I understand your feeling of obligation.
There are two types of marrow collection....marrow is also referred to as stem cells - the reason being that bone marrow is liquid and is made up of stem cells that grow up to be, among other things, red cells, white cells and platelets. The marrow is liquid and actually looks like blood - and it is truely a life saver.
One is a procedure where they extract the liquid marrow from your lower back - usually they give you anesthesia for this. You may hear people talk about the huge needles they use and, yes, they are huge but you do not have to see them. After this procedure, you will have a sore lower back much like having taken a hard fall on the ice. Usually the soreness is gone by one month and the marrow would have also replaced itself by then.
The other procedure is a peripheral stem cell one similar to when you donate platelets - it is a two armed process where excess stem cells are drawn off from your blood and the remainder returned to you via your other arm. This collection can last one or two days and is an outpatient type. To produce the excess stem cells, you are given filgrastin shots (if not this currently, something similar) for four days prior to the collection. This drug tells your marrow to flood your circulatory system with stem cells in preparation for the collection. The downside of this type of donation is that as your marrow is flooding your system, your bones ache because of the work they are doing. You can experience bone achy pain (I think they let you use tylenol for it) and fatigue similar to feeling like you are coming down with the flu. Once the actual collection starts, you start to feel better and could possibly feel absolutely normal once the collection is done. If not feeling back to normal right away, you should be fine shortly (very shortly) thereafter.
Being a young woman with three children, you may not be the first choice as a donor since when you are pregnant, you create antibodies which can transfer with your marrow to the patient. This is why they ask you how many pregnancies you have had, not children. That being said, you should be aware that if you are called, you may very well be the only donor. They won't tell you that. In fact, you could be, for example, one of five that they call for more testing. So, if you get called again, it will be for more testing for compatibility. And, if that looks good, will be called for more tests, etc. If all is well, you will be asked to donate.
This is an incredible opportunity and I look at it is that if I am the one person that can save someone else, they would also be the one person that could save me if the situation were reversed. Quite powerful.
There is a saying, and I am paraphrasing here, to the world you are one person but to one person, you are the world.
If none of this scares you off, go for it. You may never be called but then again, you might.
L.