Whats up ROW. If your plant is 3 1/2 months old you should have seen pre flowers by now. Look where the nodes are and see if you see either small white hairs or small balls. Do you have your lights on 24/0, 18/6, or 12/12?
That's a nice looking plant. Great looking stem, and leaf. Take a cutting of about 4 to 6 inches from a lower branch tip, trim the leaf from the bottom half of the cutting. Put the cutting into a glass of plain water and control the light for 12 hours of absolute darkness each day. This will make the cutting flower in about 7 to 14 days. You will then know without a doubt if you have a male or female.
Topping a plant won't affect the final yield unless there are other factors involved. If you take one plant and top it, and another and not top it, let both grow until the plant is at it's full maturity, then flower, they will both have the same amount of bud. One plant will have a huge kola and very few other buds and the topped plant will have a smaller kola and lots of other buds. The total weight of all the bud on each plant will be very close to being the same.
There are many ways that this is not true however. If you have limited height and top to fill out the bush and make many more tops, then you might have more bud than if you left only the kola growing and the rest of your grow room has empty places in it. It's all in what your growing environment is.
There are no lights, it lives in the conservatory and has natural sunlight, is that ok? When i cut my plant should i cut the stem at an angle or seal it in any way? its my only plant and not sure wether to cut it, it my 1st grow so if it goes wrong... i will be very pissed off. it dont matter about size i have plaenty of room, so i can just leave it?