How would your monster bf take care of you during your period?
Your dragon, if a fire breathing one, makes sure to warm his throat just enough so he can lay his head across your lap and warm your belly. If they don't breathe fire, they make sure you have the best medicine there is to stop the pain. After all, they can afford it.
Werewolf makes you a nest with all his most comfortable clothes. And who can forget the werewolf blanket? Aka him.
If you're dating a tentacle monster, they massage your stomach to the point you're surprised their limbs aren't going numb.
Ghosts? Be ready to see a bunch of floating things as they try to help you with chores so you can rest!
Centaurs carry you on their back whenever you have to go anywhere to make sure you get the most rest you can.
Your orc husband makes sure to drape you in as many furs as it takes to get your cramps to go away. Don't mind him bragging about how he caught and skinned every single one himself, he just wants you to praise him!
Oh? This hurts? This feels weird? Sorry! Your alien bf is just so curious about the human anatomy!