usually its fine to harvest your plant is stages. By taking of the main Cola (top) that is ready for harvesting your letting the plant put all its energy into the lower buds and they will get more sunlight this way.
If you topped it then it should have been a big cola or you did this for no reason. Only top in flower if the top cola was ready you dont regrow it you manicure and dry it........
i topped mine and i was seriously suprised at the size of the buds being held beneath all the leafs of the top. i think i am going to continue doing this til i am the bottom. be a lot nicer to end up with fully mature buds all the way down than to crop early.