calendar updates are not appearing on icloud

I've been searching for hours on this issue and any help would be greatly appreciated. I have an ipad 4, iphone 5 and a PC which I can go to icloud.com on. If I make a change or add an event on my ipad it is not syncing to the icloud. How do I fix this? If I make a change on my iphone it will sync with everything, if I make a change at icloud.com it will sync. This is only the calendar that is having the issue. I can make changes on notes and everything works. I have tried deleting my icloud account from my ipad and then add it again. I've done hard shut offs. I've turned the calendar button to off, done a hard shut off, turned everything back on and nothing is working. Please help. I make calendar additions/changes on my ipad all of the time and need them to sync.

Thanks,
Jen