Why aren't ALL of my photos importing?

I have about 6,000 photos and 200 videos(about over 100 are boomerangs but they still go in the videos album) So usually when I plug my phone into my laptop to charge it, it automatically starts importing my photos, once it's done it asks if I want to cancel or continue, I always press cancel considering the only reason I plugged it in, in the first place is to charge it. So when I finally go to import my photos and not just charge it, it says "9 new photos found". When I know that of my 6,000 photos only about 1,000 have been imported so I should have more than 9 new photos. I don't plan on importing all of my thousands of photos. Just a few hundred that way I can delete them and have more space. But I can't do this if they're not found on the computer. As far as I know both iTunes and my phone are fully updated and I know forsure that I have enough space I just don't understand why the rest of my photos werent found? Please help