Not Period Correct.
I needed two of my characters to not have sex. Fear of pregnancy is certainly a very good reason. I thought about having my heroine count the days, but just for giggles, and by giggles I mean “because I am a hopeless research nerd,” I looked it up to make sure the Victorians knew about that tidbit.
Women didn’t know about counting the days from one’s last period to determine the fertile window until the 1920s.
This was made worse by the fact that condoms were not widely available, and in some places only sold to married men.
You don’t think about just how liberating birth control was, just how great a degree of freedom is conferred by managing one’s own fertility, until you get smacked in the face with it. I have never known a time when I couldn’t just bop into 7/11 for condoms, or wander into a clinic and emerge with birth control pills, or at bare freaking minimum count days and say, eh, the curse starts tomorrowish so we’re probably clear. Also, while the consequences to getting pregnant unintentionally and outside of marriage would have had a massive impact on my life, I would not have had to cope with any societal disapproval, nor would my single mother status have any impact on my ability to be employed or rent an apartment.
What an impact this would have on a sexual relationship!
This is why good historical fiction isn’t “girls like us but in costume.” Some aspects of being a woman are universal across time and space, but other things are so anchored in context as to be meaningless without it. I hope I’m up to the challenge…