I've have aching tendons and pain fingers elbow and now knees it has been getting worse and more frequent but is not continuous what should i do?

You need to see: a health care professional for an examination and blood work to determine the nature of your arthropathy.

See gp: Needs a physical exam and may need tests to exclude forms of arthritis. If remains unclear after those things your gp can then refer on to a rheumatologist if appropriate

Arthritis possible: A Dr can assess you by asking a lot more detail about the time course + pattern of joints involved, examining you and maybe sending some blood tests & doing x-rays. The fact that you have a number of different joints affected suggests you do have an inflammatory process occurring but the pattern (knees, elbows + fingers) is not 100% typical for any particular kind of arthritis. More info needed.