Why are female bodies and conditions not more extensively studied and understood by females?

I'm a woman, born female, and have heard all my life about how under researched female bodies & conditions etc are and how it's because men always dismiss women's concerns as hysteria, periods blah blah blah. However, women have been around as long as men. Women have been scientists in all fields for a long period of time, are they not/have they not been studying female related issues either?

I debated posting this in nostupidquestions because it does feel a little silly and I know that there have been many advances, still it feels very blamey on men when women have been able to study this as well? I'm considering entering the field so any insight would be much appreciated.

Thank you!

Edit: thank you for the very genuine answers. Why have we let men run over us for this long :(