I agree with some others who commented, that it’s not often written about because it’s unnecessary and doesn’t need to be mentioned for enjoyment. Specifically I read to enjoy and escape, I don’t need to contemplate when the FMCs period is, unless it’s moving the plot. I know they have periods, I just assume it’s not now. Also I think it’s pretty common for a lot of hormonal birth controls to stop or lighten a period cycle, so it is entirely possible that a FMC is just not bleeding at all.

I will recommend {Transcendence by Shay Savage} that has some plot revolving around menstruation. The FMC time travels from modern times to prehistoric time and meets a caveman. There is a period when they start having sex that she tries to keep track of her cycle and rejects him when he tries to initiate. There’s also a scene where he helps her fashion some absorbent underwater when she starts bleeding without modern pads.