I have no personal experience of stopping PM altogether, although, for financial reasons I have cut down to a maintenace dose for a few months. The result was that developement slowed significantly but the feeling of being female and the female body odour, or rather the lack of body odour, remained. To me it makes sense to rememer that brests are comprised of 2 parts; glands and milk ducts and fat. Once the former are established, they are not going away, while the fat is much more linked to hormones, which is why many women lose size afterchild birth. What you could end up with are small and droopy boobs.
I cannot emphasise enough, that boob growth, almost totally, derives from oestrogen, whatever its source. Oestrogen does not simply cause breast growth, it has a whole range of femaninising effects, on a male body; if you take it you must be prepered to accept these other effects.
Also you must take on board that boobs are delicate and easily hurt; a bra is not just a device to enhance the shape of a woman's bust, it playes a huge role in protecting the boobs. Recently, I had to go out in a rush and ended up spending several hours, without a bra on. The relief, when I finaly found time to go up to my flat and put one on, was incredile, as my boobs were getting reall sore! Would you be able to cope with wearing a bra, all the time?
Also remember that you will be at risk of breast cancer and will need to go on a breast screening programme