Don't worry about it. It's just their baby teeth coming out including their baby k9's.
For my girl, by the time we decided to have the vet pull out the remainder of her baby teeth, she needed 2 of her baby k9's pulled since only 2 had fallen off on their own. So the more teeth you find laying around, the better! Hopefully, they will all fall off for you soon so that you wouldn't need to put them through a dental surgery.
I kept all the teeth I could find and the 2nd vet that did my girl's 2nd round of dentals saved me her teeth too even though I had forgotten to put in that request.