Then why are they getting pregnant and having children? At least for the time they are pregnant and giving I will consider them to be women.
Because human being often desire to reproduce.
"At least for the time they are pregnant and giving I will consider them to be women."
Regardless of what you consider, trans men consider themselves men. Their circumstances and medical needs aren't the same since they typically take testosterone and look like average men.
Another reason I don't think your wording works is that the majority consider the concepts of "man" and "woman" to be permanent things.
I honestly don't understand why I have to care about that anymore than if they thought they were wolves.