military period

Yesterday I had duty on my ship and I had to stand a watch that sat down for four hours. So at the end of this watch I had to pee. I went to the bathroom and when I pulled my underwear down I saw that I had started my period, and from the amount of blood I'm guessing I had starting like 2 hours before I saw it. And I didn't realize I had started because I wasn't cramping, no back pain, and the flow wasn't heavy so I didn't feel it. So I had been sitting there bleeding for two hours without knowing it. So now my nice, clean, lacy white underwear...are ruined and it really upsets me. That's all.