My recomendations/comments:
1.) No worries about the lower growth. Embyro leaves as you called them (actually called cotyledons) as well as the first set of true leaves will die off within the first 4 weeks, and begin new growth at that node. This is for branching.
2. Wipe the dirt off your leaves.
3. You might start seeing pre-flowers within the next 2 weeks.
4. Keep it up, amigo.