I have heard that dragonflies have stingers that they never use.
It's still odd to have one flying around you.
If you are referring to an ovipositor, only female insects have them. Wasps do in fact use them for defense, but if you are afraid of something with a "stinger" AKA ovipositor, you are actually afraid of every female insect, not just dragonflies.
By the way, in case you didn't know, an ovipositor is an external organ for laying eggs.