From the Skyrim Kink Meme (this is the short version):
F!dragonborn gets her period. While kicking bandit butt with her werewolf hubby Farkas. But she doesn't know it. Until Farkas turns back human and is going crazy over her because he could smell the blood, but can't detect any injuries. She's all "wtf I'm fine" until she goes for a bathroom break. Then she's like, "Ooh, I get it now."
The next week is hell for everyone. DB is usually a softspoken, polite young woman, but now she's angry one minute and crying over something insignificant the next.
For once the night air wasn't as freezing as it is on most nights in Whiterun. But for Sylori, it didn't matter either way. From her position on a nearby hill, the Imperial silently monitored the bandit encampment. Once again, another group of bandits had claimed Halted Stream Camp for themselves and started attacking travelers. So, by request of the Jarl, Sylori and Farkas were to get rid of them. Instead of going in, swords raised and arrows flying they decided a case more stealthy approach.
Farkas would enter the mine through the spike pit in the back, transform and then herd them out into the night so she could pick off the stragglers. And then they could return to Jorrvaskr, eat supper and return to their room to play 'sheath the sword'.
A howl and a chorus of screams brought her out of her thoughts. She watched as the surviving bandits poured out of the cave, some in a state of undress. Behind them a large werewolf shot out, mauling anyone that got in its way. Sylori stood, bow and arrow in hand, and began picking off bandits from her perch. The bodies started piling up and not even ten minutes later, the only movement she could see was the changed form of her husband searching for any survivors.
Sylori was about to put away her bow when she spotted a bandit flee the camp. And as luck would have it, Farkas caught sight of the thug and gave chase. Sylori pulled out an arrow, notched it and waited for the right moment. The bandit was running towards her position with Farkas closing behind. Just as Farkas was about to pounce on the bandit Sylori fired the arrow.
It sailed through the air and hit the bandit, propelling his body back into the werewolf's. The wolf buried his teeth into the brigand's neck and tore out a large chuck of flesh. The body fell to the ground. Sylori blew a dark strand of hair from her eyes and smiled as the werewolf slowly approached her, its body changing with every step. Dark coarse fur was replaced by pale skin, the burning yellow eyes turned gray. And soon enough Farkas was standing before her in all his naked, Nord glory.
She grinned and tossed him his armor. "And that makes eight for me. I got the last one," she proclaimed triumphantly.
"No you didn't," Farkas pulled on his boots. "That kill was mine."
"The arrow sticking out of his head says otherwise."
He opened his mouth to retort but a look of confusion washed over his face. He sniffed the air and gave her a worried glance, "Did you get hurt?"
"No. He never made it to the hill. Remember?" Undeterred, Farkas moved towards his wife and proceeded to sniff her neck. The scent grew the closer he was to her.
Sylori took a step back and started for the camp. "Come on. Let's sack the place and go back to Jorrvaskr. And then you can be as territorial as you want." Farkas nodded and followed his wife. If she said she was all right, he believed her. But that did nothing to appease the wolf inside.
They returned to a quiet Jorrvaskr. Only Tilma was still awake. Farkas went to sit at the long table to eat while Sylori descended down into the sleeping quarters to change out of her armor. She returned, now wearing a simple shirt, trousers and robe, and sat down next to her husband. Farkas stopped in mid-chew and sniffed the air. The metallic scent was still emanating from the Imperial, although not as heavy as before. He leaned over and whispered into Sylori's ear. "Are you sure you're not injured?"
She took a swig of ale and whispered back, "Positive."
The look on the Nord's face clearly said he was not convinced. The Imperial let out a sigh. "My bleeding period has begun," she stated plainly. "That's what you smelled."
"Oh, really."
Sylori eyed her husband suspiciously as he bit into his mammoth steak. "You have no idea what I speak of, do you?"
His silence was the answer she received.
She let out a hearty chuckle. "Didn't your father ever inform you?"
Farkas shrugged. "They taught me how to swing a sword and how to craft armor."
"Fair enough."
They ate the rest of their supper in silence. As they returned to their room, Farkas asked yet again, "Are you sure you aren't injured?"
"Ask me again and you sleep outside," Sylori growled, "In the cold." Farkas could only nod mutely.