well, theres many factors you need to consider: (this is coming from a girl with a gender fluid best friend)
-what days do you feel feminine?
-what days do you feel masculine?
-what days do you feel neither/both?
-what clothes are you comfortable in/not comfortable in?
-which gender feels like the best one for you? (if you can't answer, skip)
those are a few things to consider, however I recommend doing more research.