Missing photos after updating iPad

HI,

i updated my iPad yesterday, after deleting quite a few apps and some photos to get enough storage. Now, there are several hundred pictures missing. I am confused by the photstream discussion, they were on my camera roll which I can't find now. It seems they were on my iPad because the storage freed up when I deleted them. I bought iCloud storage because it said I was running out. anyone able to help me find them?