I am a 27 year old female in otherwise good health. For the past 1-2 weeks, I have been experiencing lower back pain (including the buttocks). It was mild to moderate. When lifting my right leg off the ground while sitting, it would irritate my lower back. Yesterday, I went swimming and had to use the stairs at an apartment building, so that's the only physical activity I did (mind you, I am out of shape - though I am still awesome). When I got home, I noticed a sharp pain in my lower back that comes and goes - but damn, it's sharp. I also noticed my hip is hurting as well, particualrly when I raise my leg or walk - and there's some discomfort on my knee too. Should I be worried that this is serious? I am truly concerned and need some peace of mind.