A bunch of my notes have dissapeared from all my devices

I had around 100 notes and just the past few days I've noticed that I now have only around 20. I use notes extensively and now a bunch of them are missing with important info to me. The only thing I can think of is when I did a update to my iPad. I have my notes synced to icloud and have many devices to access it - iPhone 4s, iPads, mini mac, etc. I read all the histories here but these are old. Would love any help from anyone.