do a test, it could be a ingrowing hair
there are many symptoms of pregnancy that would be present before any type of bump would be noticable... women usually dont start showing till about 12 weeks, and even then it would still be a lot of bloating, a lump to me is more like a cyst type of thing not like a baby bump... so in order for anyone to try to help you we need a little more information... like how big is hte lump or bump, how long ago did you notice it, have you missed a period yet...
Lumps could mean a serious health problem, a pulled muscle, lots of things.
They don't normally mean pregnancy. Can you describe it a little more?