Just will reinforce what has already been said. Take a gravity reading, wait a day or two and take another. If they are the same, or withing say .001 I would say you are done and it is ready to keg or bottle. Remember, once in the keg or bottle you will have to wait another week or two for the crud to settle and the carbonation to do it's thing. The biggest takeaway I have learned from this hobby so far is patience. Of which I don't have much. LOL. My last batch I left in the fermenter for about two weeks, had to time it right for the dry hops and the transfer to the keg. Once in the keg, it took about another week or so to carb up and be ready to serve. I have noticed after about another week or so, the flavors are much better and the beer, to me, has a much better balance. But that might just be me being me. LOL. Either way, gravity readings are the only way you will tell if the beer is done fermenting. Rock On!!!!!