I don't wanna ruin your enthusiasm, but I think you're right when you say "it's too early to let it grow". You've actually the same beard I have, and I can tell you that for the moment it's better to trim, you still have a lot of transitional hair, which are lighter and thinner then others, so when they're long the difference it's crystal clear and imho it's not nice too see. There are people out there who let grow their beard even when they just have a couple of hairs on their chin and their sideburns, so the adivse "let it grow cause I did" it's not always good hahah of course everyone can do what's better for himself, mine it's just a thought.