I Am Women Of The Age Of 51 - And

I am women of the age of 51 - and for the last 6 months I have had problem with ache , stiffness and point in my joints and muscles. I have been to my family doctor and they ran some blood work, which all came back fine. They are telling me that it is because I am getting old and this will happen. I am sorry but i think this is more then old age. I also have MS and i have talked to them and they tell me it is not MS. Can you give me some advice.
THANKS