Ask HN: discussing free time contract work with my full time employer

I’m a full-time dev at a large tech company, and am currently based out of California. I plan on doing contract work in my spare time, potentially doing things related to what I do full-time. I have not signed a non-compete with my company, and to my knowledge no contract stipulations preventing me from contracting. However I still want to talk to someone from our legal dept before doing so. Is this a good idea? Should I tell them at all?