What is the general amount of time before being “official”?

I’ve been talking to a girl for about 6 months ish now we’ve only gone on 3 dates because i’m very busy and currently saving for a car. (i’m 20 she’s 24) Neither of us have a car right now and don’t live in a walkable city unfortunately.

Despite this her and I have a lot of things in common we both haven’t had “actual relationships” as in something longer than 2 months. But we both like each other. Is this still too short of a timespan before calling each other girlfriends??