I used to think I was "cisgender", but now I've been thinking that I'm FTM, Non-Binary or a masculine lesbian. Also, I've started "packing" last year and it makes me think differently about my gender. I don't know if I'm FTM, Non-Binary, or somewhere on the gender spectrum.
What made you decide to try packing and what other things are there that make you think that you might need to live your life as anything other than a woman? I believe that anyone who can comfortably live within the confines of their birth assignment should do so, transition is difficult and even after living opposed to what society wants us to is not an easy task.
I don't know why I started packing. I just decided to do it and I felt differently when I had stuffed the sock packer in my underwear. This is when I started questioning my gender identity. Am I FTM, Non-Binary, or somebody that wants to go against what society wants from women?
From just what you have said you could be any of the above that you listed. If all that you have done or even considered doing was the packing and maybe dressing more masculine I do not think that it even has to do with your gender identity. You can still be a cis woman and present masculine, have stereotypically masculine hobbies and all of that.
It's a difficult question and there is no one right answer. Definitely this is some form of crossdressing, so it's somewhere on the gender spectrum. However on which side you fall or in the middle, depends on what the bigger picture is. Or maybe it isn't crossdressing for you? Maybe it just felt right physically, because you feel like something should be there? On the other hand, it's not very female to feel like having male genitalia. Anyway, you might fall anywhere on the gender spectrum, it really depends on what gender you feel that expresses you best.