It is possible that you have an occult source if infection, usually an urinary tract infection
that can cause these symptoms.
So please get a urine dipstick done and ask them to send for culture sensitivity studies as you are on immunosuppressants. Normally if the urine dipstick was borderline abnormal, they wont send but ensure this is done due to the medications you take for lupus
Also a thyroid
function, complete hemogram, CRP, U&Es must be done at the same time.