I dont think you can put a time frame on love or friendship. Everyone will tell you something different, but how do you feel?
Is the relationship good? Does he take care of your needs and do you take care of his? Are you both committed to each other? Do you trust eachother? Can you count on him? If you can answer yes to all these questions then I think you should be together no matter how fast you moved in together.
Sometimes you just know these things. So what made you ask that question? Are you having doubts or has someone said something to you?