I don't really see why it matters either way because it has only been four months. I'd wonder if whomever said it after four months truly knew what they themselves felt. That early in a relationship there is still a strong sense of infatuation and everyone is trying to put their best foot forward to please the other person. Lets see if he is saying that he loves you after a year, then you both will have a better idea of how you both really feel.
...one can be sure of nothing until it has already happened...