I say if your s.g. is 1.018 or under, go ahead and put it in secondary if it's a convenient time to do it. But, you could leave it in primary, too, without any harm at all.
How's that for being helpful?
Seriously, no reason to worry about autolysis yet. I do secondary all my beers, so I move them around 1.018 or less, or about day 10 if I don't take s.g. readings. If you're still getting 3 bubbles a minute, you can decide what you want to do with it.