At the beginning of my PN mine started similar to that.

My PN is in my feet but in the beginning before I knew what was going on, I kept thinking I was losing feeling or sensation on my left ankle but it would come and go and I thought I was going crazy.

Eventually I touched the back of my heel and it was completely numb which is when I realized I was not crazy and it was time to do something. Periodically I had other sensations of tingles, burning, etc. on my toes but again it was so brief, and only periodically, so I ignored it.

Then of course things progressed to both feet and full blown PN.