Im 14, weighing 65-69 kg and im a female. I have pain on my lower left part of my back 3 days after running during PE. It has been a week now and it still hurts. I also found that i have a random bruise on the back of my elbow which is less reddish and purple-ish. I feel dizzy whenever I try to stand up quickly and i am always tired/sleepy. My skin has loss most of its tan but now it looks a little pale. Not too pale. Should i see a doctor?