Pregnant or not?

Okay so I'm about to be a paranoid cat mom here.. I brought home a (roughly) 6 month old kitten on Tuesday. She wasn't extremely malnourished, but she was a little skinny in weird places, and small for her age, due to being fed strictly cows milk for the last 6 months. Now that I have her on cat food she already looks much better, but her stomach is a bit larger than the rest of her. While she was sleeping one day I was rubbing her tummy and felt weird lumpiness, and upon further inspection just now, I can say there's one lump right behind her left rib, and two lumps behind her right ribs, they are fairly hard, and I felt movement but it didn't really feel like kitten movement (I'm actually comparing to puppy movement here), I'm assuming it was food digesting, given she has gas anyways. But back to the lumps. I'm not concerned that there's something wrong with her, because the vet palpated her stomach a whole bunch just two days ago, (checking for UTI) and didn't mention the lumps. But I'm thinking, not pregnant either, because they didn't say anything (unless they were assuming I already knew?). So anywho, I'm hoping (and assuming) these lumps are just internal organs that I can feel, givin the condition her body is in from the poor diet.
And another note, her nipples are NOT pink.
I did try to get pictures, just for reference, of her belly, but forgive the quality because it's hard to get good pictures of a squirmy cat in a dark room with no one to hold her for you.

Could you phone the vet and ask?  He perhaps didnt mention the pregnancy, as its not a sicknesness.  Exactly as you yourself speculate.

I dont think the lumps would be felt in just two days for an amateur, while they werent felt by a vet.  Also, she is beginning to fatten up now, so its actually a little more difficult now.  So I think, he felt them too.

You are his paying patient, so its OK you do phone and ask.  If necessary, let the assistent relay your question.

Otherwise, an unprotected female out in the open, usually does gets pregnant, if she isnt sterile by nature. Very few are...  Young age is not good protection, many gets fertile at this age about 6months.

So normally I would suspect she is preg.

And if you do have experience with pregnant dogs and puppies, your instinct and palpitation  is surely better than average here.   The palpitation isnt that much different, I guess.

I agree with contacting the vet again. Has she been outside at all? If she has, then I tend to agree with @StefanZ  it's highly unlikely for a female that age not to get pregnant if she's been outside. The lumps may or may not be related to the pregnancy. You could have been feeling some internal organs. 

I do wonder about her being fed only cow milk for so long. She could be severely malnourished and that could have affected her fertility. What has the vet said about that?

Yes her previous owners had her outside. She is inside now with me, and will stay in until I get her fix, and probably even after that. When I told the vet she had only had cows milk he just went "ooh" and shook his head a little. He also described her as "petite" not malnourished. He's the best vet we have around here for small animals, but sometimes I wonder if he's a little out of date because he's not the best at responding to some questions. Especially about cats. He's more knowledgeable with dogs. I may call though