OH MY LORDY I never thought I'd have a relevant time to bring up this story, but here it is!
When I was 17 I went on exchange in Japan with some other students from my school, 5 girls and 10 guys. This was only the second or third night of the trip, so I didn't know some of the guys very well at all (we had classes in separate genders) except for one, who I happened to have an almighty crush on. We were staying in a quaint traditional Japanese inn (ryokan), and so after bathing we all put on cotton kimonos to lounge around in. On this fateful night I was sitting on somebody else's futon with my back against the wall, having a discussion about everything under the sun with two guys I hardly knew, and the guy I had a huge crush on. It gets to about 11pm so I get up to leave and go back to my own room to sleep when... SURPRISE TRIP TO THE RED SEA. Blood. Blood EVERYWHERE. All over the crisp white sheets of this futon, and all over the back of this white cotton kimono. Potentially two whole hours of seeping leakage had occurred without me knowing. It was like my uterus knew that I was unarmed and wearing white and decided to strike with a vengeance. I wasn't even expecting my period, I was mortified.
As the guys stand there like stunned mullets, I whip the sheets off the futon and run down 2 flights of stairs with one hand covering my blood stained butt to my room to get some clothes, and then down to the reception spluttering in terrible Japanese about needing fresh sheets.
In the interim, the boy who's bed I had christened with my womanly goop returned to his room to find it sheetless. He'd been playing cards in the next room. My guy crush (bless him) was prone to blood noses and quickly explained that he'd gotten a blood nose and I had volunteered to get new sheets while he cleaned himself up.
It could have gone a lot worse, but as a 17 year old in the presence of a cute guy I definitely wanted to dissolve through the floor.