Painful Lump in lower left side of belly

I am 23 yrs old and around 20 pounds overweight. I have been having pain in my lower left side of my belly for a few weeks now. I can feel under my skin 2-3 very hard lumps that are painful when pushed or squeezed. I have lumps on the right side of my belly also but these do not bother me at all. I have also noticed that when I urinate, the lumps on the left side bother me. And now just recently I started feeling a new lump close to my groin area that is much smaller (about width of a pen) that shows up when i urinate, this lump also causes discomfort. The pain is not much for any of the lumps but it is just annoying. I would not like to live like this forvever. I have had an ultrasound done with no results. I am going back to see my Dr. this week. Even sitting down I feel discomfort coming from my lower left side. The lumps are cylindrical in shape. I was wondering if this could be a hernia that was missed with the ultrasound, some kind of STD, fatty pustules, or something else entirely. I don't think it could be an STD though because I had this several months ago in April but then it went away. I have only recently been sexually active. Thanks for your time.