I Was Wondering If My Swelling Below My Knee On

I was wondering if my swelling below my knee on my left leg could be caused by donating plasma twice a week, I am male, 388 lbs, 6'2" tall, i have been a big guy my whole life. I do have some some varicose veins in the back of a both legs. I need to know if this could be something i should go to the Doc for. I just recently lost my job and i do not have insurance at the moment. Please let me know what you think. Thank you very much for all your help in advance