I have some lavender growing in my garden but have no idea if it's edible. Are all varieties edible?

Is it possible to share a photo of it? I think some varieties are more edible than others. There are a lot of things commonly called lavender, not all of them are actual lavender.

This column on lavender bergamot might help:

https://food52.com/blog/10556-lavender-bergamot-a-wild-plant-for-your-garden-and-your-cookies

unless a pesticide is used it should be fine
http://whatscookingamerica.net/Q-A/LavenderCulinary.htm