My daughter hit her knee really hard on a sharp corner of bench last night and it swelled up instantly. It wasn t on the knee cap it was to the side (inner aspect). She couldn t bend it at the time and put ice and elevated it then went to sleep. In the morning the swelling had gone down and she can walk. She wants me to take her to a Doctor incase a blood clot needs draining or something. I told her maybe she should have rested today and iced it again instead of going shopping. At what stage would I have to follow up with a Doctor?