iCloud photo library not updating

I've noticed that when I take pictures on either my iPhone or iPad, it's not showing up in my photo library. My ipad sometimes says that the iCloud Photo Library in XX days (currently around 43 days). This is the case, even though I plug in my phone every night and it's on Wifi. I don't change my iPad every single night but it's at home on wifi the majority of time and at the bottom of my picture folder, it says it's downloading 16 items. I have 3 gb out of 5 gb of storage available and I the Photo Library is enabled on both devices.