lumps in stomach

Hi I'm 16 years old and about 2 months ago I found a lump in my stomach and i went to the doctors, they said it was probably just fatty tissue. I found three more a few weeks ago went to my doctor this time and she's sending me for an ultra sound. Today I was checking my stomach again and found two more.
Other symptoms I have(which I'm not sure if its related) is that I've been feeling naseous and I've been having episodes where I start blacking out and I can't stand and I get chills, I'll lay down and after a few minutes it goes away. I guess I just want to know what the possibilities are that this could be, if you could please just reply back, thankyou