It looks great for 3 weeks. At 2 to 3 months, it will really be filled in well. Heck, even right now I would say that you already have a nice full beard. Let that stache keep bulking up. Trim it at the lower edge of the upper lip. Let the other hairs keep growing so they all meet at the same point at the lip edge and that will give you a nice thick stache, which will make your overall beard look even better. Your neck and cheek lines are fine for now. Keep them there. I usually move first time growers over to the First Beards forum, but you are not going to really need any help in growing your beard, so I will keep you here as you are already on a journey growing your beard. Keep posting weekly updates and let us all cheer you on as you grow along!
Patrick