Dena is right, a few months on hormones won't make a huge physical difference. However if you are planning on transitioning to your identified gender at the same time then yes, coming out is a necessary step. A lot if it depends on how confident you feel and how much control you want to have over the message people hear. If you tell a few people and expect them to pass the word along then you will likely be very disappointed if not distressed by the final result. As each person tells another person they will flavour the telling with their own perception, ignorance and bias...what you want people to know and hear might not necessarily be what they are told. Telling everyone at once, while potentially really scary does mean you've told them all the same thing, they get to know what you want them to hear, they know the person not the gossip.
