Finding blood in my step sons underwear

I was in the laundry room and opened the closet to look for the fabric softner. And I found a Wal-Mart bag full of boxer briefs. I know they aren't my husbands and my daughter (19) wears thongs so that only leaves my 14 year old stepson. The were hidden under some blankets and when I took them out there are 5 pair with blood on in them. It looked like a period accident in them. At first I did think maybe my daughter for some reason got into boxer briefs but her tampons in the bathroom are untouched. Plus she wouldn't have hid them in the closet. She would have just washed them. My step son is back for the school year "visits his mom in El Salvador for the summer. He didn't last year because of covid and went a month later than usual this summer. My husband isn't even home right now. He's 9 hours away for work related stuff... He'll be back Sunday. What should I do until then?

Edit: idk if female hemorrhoids are different from male but I never bled that much when I had them. It looks like when you wake up in the morning and realized you got your period last night.