yesterday,both thigh muscles went completly weak,today they feel like ive run a marathon ??

hello everyone…i havnt been diagnosed with ms…but am having test…the one where they put the needles in your muscles !! - anyway yesterday,my legs went completley weak and shakey,litteraly couldnt bear my weight,but subsided after about 1 hour,but then felt really weak the rest of the night…and today the muscles in my thighs are so tender,like ive run a marathon,anyone had this ?