Hey growmie your plant looks great and it will stretch when the flowering phase starts it can double even triple from time to time in height so I wouldn't worrie most growers would rather short and bushy plants, you don't want them to get tall with week branches cause they won't support the buds as well as shorter and thicker branches. But if ya want them to stretch put you light's further away from them and they will but I wouldn't recommend doing that happy growing.