Help I am a mess!!

I got period on Christmas <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">Eve</a> as I was supposed to stay overnight and all day today with my boyfriend and his family. I brought extra clothes, thank god, but my period is out for revenge. I’ve stained my spare pair of underwear and I’m nowhere close to being home. How can I clean my underwear without anyone noticing??? Helpppp!