Most definitely see your doctor. It doesn't sound like a blood clot, that would usually present as a swollen, tender, or reddened calf. That would not explain pain in both legs, since while not unheard of, it is not too likely to get a blood clot on both sides at the same time. It is impossible to take guesses at what any lump or bump might be without seeing it, and especially without knowing the details of your medical history, your age, etc. Superficial veins can get lumpy with clots or varicosities, but it would be obvious to you that they are veins. There are lymph nodes in all parts of the body, and in the legs enlarged lymph nodes are usually first felt in your groin. Cramps have many causes, as do lumps and bumps, and looking up the many different causes will certainly be scary considering the serious diseases than you will find listed as possibilities. Generally, lumps will fall into three causes: Infectious, Inflammatory, or neoplastic. Best to have a doctor, not the internet medical sites, as your first explanation so that you can narrow down your self education to what is likely, and not all those other problems.
I hope you are feeling better soon!