Just by your description, I cannot make out what the lump is that you describe.
Whether it was inside your uterus
( you wouldnt know it then ) and if it is 10 cm below your belly button, it would be on the skin, in which case it could be a boil, or a lipoma
Spotting is not normal for 2 weeks, followed by a pus discharge especially.
Could point to impending miscarriage
or a pelvic infection
You need to consult your gynecologist as based on the scanty information supplied, it is difficult to diagnose the problem
You could write to me in more detail, if you wish.