8 weeks is kinda tight... i pulled off a single plant in 73-75 days and i thought that was pretty short, i even harvested a week early , it wasn't an autoflower strain, just bagseed... i pulled off a 26-27 day veg, topping it once, when it healed put it in 12/12...
given it was my first grow im kinda proud i got almost 20 grams....
just top it and veg it for 25 days or something, then 12/12.... good luck