Photo Library not uploading from iPhone 6

Hi, I have a new iPhone 6, updated with 8.3. I activated the Apple Library more than three days ago and still no photos got uploaded. I tried signing out iCloud and back on but still nothing happening, with the iPhone fully charged and connected to wifi. I have 20Gb of space in iCloud and only around 1,300 photos to upload. Is there anything you can recommend ?
Thanks a lot,

Regards