What Causes Pain And Numbness In Left Arm?

Hi, I am a 28yo female, my left arm has been aching and heavy but also numb for about a day and has also now started tingling in my left hand. I've previously had a benign tumour in my right temporal lobe removed and experience similar symptoms so am starting to get concerned. I do spend a lot of time at a computer for work. I wont be able to see a doctor until next week. Could you please give me advice as to what may be causing it?