Some notes under Contact have disappeared

I keep important notes under my Contacts on my iPhone. However, two notes, the ones I especially didn't want to lose, disappeared from those Contacts sometime in the past year. All other contacts still have their notes. I suspect I clicked on something in my phone, thinking that it would help me to NOT lose those two notes, when in fact it caused them to disappear. I have not used iCloud to back up my phone, so they aren't there. Any ideas or suggestions about where they might have gone to, and how I can find them again? I would appreciate any and all the help I can get! :)