I have been having a problem with my knee.It started about a week ago. I have lump that seems to be getting bigger it only seems to hurt if I am walking or if I try to stretch my leg or during the middle of the night it really seems to hurt like it tenses. I was told it could be from inflammatory so I have been taking ibuprofen but it does not seem to be going away its getting bigger what could it be? I am worried it could be a blood clot.