I slipper coming down the outside steps to the block of flats I live in last night. Put my foot down the last step, never saw the mud from the recent rain, my leg shot out & I ended up sat on the steps, my knee on the other leg is agony, I managed to limp in to my flat & have had ice pack on my knee, have taken ibuprofen & painkillers overnight, I can walk if I am holding on to the wall, but can't totally straighten my leg & my knee feels like it is going to give way. If it isn't any better by monday would I be wasting my time to go to minor injuries?