How do you know fermentation has stopped????
The airlock is not a fermentation gauge...it is a valve to release excess CO2...not a precision instrument...If it is not bubbling it could just not have an excess of co2 to be released, or it could have fermented out...NOT that there is anything is wrong...
Read this...then leave you beer alone for 10 days, and follow the suggestions in there (hint...it involves a hydrometer, not an airlock)
I am 99.9% positive that there is absolutely nothing wrong with your beer, just that you are nervous and new at this.
Leave the beer alone...the yeast know what they have to do...
(The beer is fine...you just have a mental illness that around here we call noobitus, the propensity to worry too much about something that at this stage you know very little about...Your beer is much stronger than you think it is. And it is perfectly fine....so walk away for awhile.)