Virginia, please don't be alarmed by the lump you have found. You need to visit your physician promptly to get an appropriate diagnosis.
I am very concerned to learn about the response you got from 'Yahoo answers'. It is quite irresponsible when people respond so blatantly to queries such as yours, without having the relevant expertise to do so. Might I suggest that the lump could very well be due to excess fluid that your system might not be adequately draining away.
The best way to put your mind at ease over this health question is to seek expert advice pronto. This will stop you worrying yourself needlessly.