I am a 34 yr old woman, I have been doing heavy work, remodeling a house with stone work, and shoveling tons of dirt myself, for about a month now. The dirt shoveling just started about 3 days ago and I noticed that a vein has started to stick out on the outer side of my left knee . I have two bad knees, surgery on both when I was 15, and they are swollen frequently. But I have never spotted a vein like this before. Should I have any concerns?