Thank you Niranjana and UnamiLalu for your kind replies- I will try to see my rhuematologist and see what she thinks although I think I mentioned it once to her and she said it could be aging..hmm
I think I know my body better than that.

Cathy, I am unsure what to make of that, but the fact that it is intermittent and not painful is reassuring.

@UnamiLalu--Has your rheumatologist examined you? It could be painful soft tissue inflammation, as lupus can affect our entire body. I hope you get some relief.

This has also been happening to me for almost 2 years now.but it's painful with a burning sensation sometimes

It is just above the knee- sometimes involves the kneecap but mostly above
Not red or painful and not the rest of the leg at all- has been happening off and on for many months

Is it localized to just above the knees, or is the whole leg swollen down to the ankles and feet? Is it painful, red, or tender to the touch?