Christie and Emma,
All aboard on the TG train!
Seriously, in my opinion, trying to decide on gender and sexual orientation, or sexual orientation BEFORE gender, is confusing.
It is best to find your true gender (internal gender), THEN sexual orientation, IN REFERENCE to the true gender, to know sexual orientation.
Just as an adolescent experimenting with sexuality does not reflect on true sexual orientation (exploring homosexuality does not make him or her a homosexual, for example), when one first transitions, just like an adolescent, the person may explore different sexual orientations, before finding the sexual orientation that is right for him or her.
Changing your mind on your sexual orientation does not make you a liar . . . as we all are a work in progress . . .
Monica