Give it a little more light, feed it regularly with any good houseplant fertilizer, and, if all else fails, give it 14 hours a day of unbroken, complete darkness every night.

If a plant is too vigorous and not flowering it can be because the feed that is given is too high in nitrogen and not enough potash. Some houseplant fertilizers seem to be best for leaf plants and some for flower plants. I give mine a tomato type feed. A too big a pot can also cause the plant to make green growth and not flowers.

I have never fed it in its life becuse its so healthy and grows so well Do you think that could be the problem?

Maybe you are being so kind to it that it feels no need to try to set seed? I don't feed mine very often and often don't water it until I notice its looking a bit unhappy, but it has five flowers on it at the moment, the most its ever had at one time.

Where do you keep yours Steragram Is it in light or shade?

It is on a north windowsill and gets no direct sun at all. I inherited it from my mother and she grew it successfully on top of the piano several yards from a window. It has never grown very big on my spartan treatment but it does flower. And if it got any bigger it wouldn't fit on the windowsill...