We typically think of gender as an internal sense of identity and not as adhering to some stereotype. Generally speaking if you identify with the gender you were assigned at birth then you are cis.

Often the way trans people realize they are trans is by realizing something is wrong or that something else brings greater joy, that is to say via dysphoria or euphoria, not just via directly feeling gender. I think for a lot of cis people and eggs it's difficult to feel a sense of gender because they're so used to how things are the way a fish won't feel wet if it has lived its entire life in the ocean.

As a trans person, I'm glad I don't have periods or have to worry about pregnancy. I also don't want to deal with any of the discrimination women deal with around where I am. I'm sure many cis women agree about all of those though.

Stereotypes don't really matter.

What being trans means can vary from person to person. For me, I realized I wasn't cis because I didn't like some of the physical traits associated with men (hairy, penis, balls, body shape) and I realized men weren't being ironic when they liked those things or otherwise performed masculinity.

I didn't think I experienced much dysphoria and that didn't change that much* until I started HRT 2 years after realizing I was trans.

*At least by the definition of dysphoria I used before realizing I was not cis.

Broadly it's just "wants to change gender from the one assigned at birth" vs "does not".

Gender is ultimately just made up and the entire definition hinges on that, so idk if there's a straightup answer. I'd say if you want others to perceive you as male, you're probably cis. If you don't care then maybe you are too, generally with these labels whatever you think you are you are.

Fwiw I'm (closeted) transfem and one of the things I'm happy about is that at least I don't have to deal with periods lol, I feel like actively wanting one would be an obvious sign of being transfem (and i guess also a strong sign of being cis fem if someone afab really likes having a period?) though because otherwise it just seems really annoying to deal with.