I am 63 years old and have had Fm since I was very young, I was not diagnosed until I was 38, I am B neg. My sister and my 41 year old son also are rh neg and have Fm also. I never had the rogahm shot. I have 3 children , all of whom are rh neg. My sister has 2 children who are neg. My daughter has 4 boys who are rh neg. Am watching my 38 yr old daughter for signs of Fm. My personal belief is that it is triggered by hormone changes in the body . I had no pain until my progesterone got very low and thyroid was low. My sister never had any problems until she had ovaries removed. My son had mono in highschool and he believes his fm started then.I never thought about the rh neg blood type being a connection . I will be looking at this and checking the board to see if anyone has any more info. A word of advice----don't let it slw you down much. Stay active and involved with life and you can beat it!