When I'm dealing with a particularly painful period, like I am right now, I pretty much always revisit this fic, all about a guy taking care of a girl he likes when she's similarly suffering. Even if you don't watch the show in question, I highly recommend it. It's all kinds of awesome and smile-making and comforting. It certainly makes me feel better.
It's Our Time by fringedweller
NCIS: Los Angeles, Kensi Blye/Marty Deeks
It's Kensi's time of the month and Deeks is being surprisingly cool about it. When he's not being hot, that is.