Ipad one calendar missing after icloud on

Hello,
today I have turned on icloud on my ipad. After that in couple minutes, i have checked my calendar. I have realized that one type (marked green) of my events has disappeared. All other calendar entries has stayed, but not that one (most important!). Not even on http://www.icloud.com

Has anyone had this issue? Can anyone help me how to get back my entries? (my last backup is 2 months old - I know, my fold)

Thanks!