I don't know what it could be, I don't sleep in anything pink. The only think I can think of is my sweat, but I didn't think people could sweat the color pink? Do you have any idea of what could be causing this?

The entire sheet, or just areas of it? Pink?

What do you wear to bed?

What color is the item you wear to bed?

What type of material are your sheets, and your night clothes?

Where on this sheet are you seeing the pink "stain"?

Is this a nightly occurrence, or sporadic? If sporadic, when, and how often?