Will he care since he is mature?

My boyfriend is sleeping over in my bed with me for the first time tonight (just sleeping). I am staying the weekend in my college apt dorm. When I got here I realized I have stains on my sheets from that time of the month that did not come out in the wash ( two roughly the size of a quarter and a cpl small surrounding dots). I am trying to wash them again,.but.I.think the stain is set. have a spare set but they are very cheap and rough and uncomfortable, and have been stored under my bed for a year so they are probably musty and I won't have time to wash them too. And I can't afford.new sheets at the moment. Will he notice or even care about the stains? He isn't shallow at all and has always been pretty mature about stuff. He also says he knows about stuff finish of living with an older sister growing up.