i upgraded my iPhone 6 to 8.1.2 and lost some pictures and some contacts. they are not in the iCloud
These two Apple documents might help you with the photos:
Get help finding your Photos in iOS 8 or later - Apple Support
Migrating from iPhoto for iOS to Photos on iOS 8 - Apple Support
Where have the missing photos been before the upgrade? If the photos have been in the Camera Roll, you could try to restore them from an iTunes backup, if you made a backup before the upgrade, because the camera roll is included in the backup. (iCloud: Backup and restore overview)
Photos in your "My Photo stream" are not included in the backup, however. Photo stream photos need to be downloaded to the camera roll, because iCloud stores them only for a month.
upgraded my iPhone to 8.1.2and lost pictures
