Welcome aboard to the hobby and forum.............specific to your question, hydrometer readings are the most reliable. Visually, you'd want the airlock to be quiet for at least 60 seconds between burps. Then you'd confirm with a hydro. If the beer is causing a burp every 11 seconds then it's still fermenting and creating CO2. (And if you bottled, you might create explosive bottle bombs as ferm continued in the confined space of the bottle.)
If you have time, you could search here on bottling or fermentation and see people's opinion. I'd also recommend you buy Palmer's How to Brew - it's a great book for any home brewer. You can read abbreviated sections online. Chapter 8 is about fermentation. You'll read that ferm time is highly variable. Generally, more problems arise from rushing to bottle than by waiting a few extra days or a week.
http://www.howtobrew.com/section1/chapter8.html