Ivory duvet cover with blue stripe

I lost my ivory duvet cover with a thin blue stripe, Queen size cotton percale from IKEA. Yesterday around 3pm I was walking back from Waterstones on Parliament Street, near The Shambles in York when I must have dropped it along the sidewalk. It's a clean ivory color with a faint blue edge, and there's a tiny coffee stain on the bottom-right corner plus a small 'LM' initials embroidered on the inner corner. It has sentimental value—my grandmother gave it to me, and I really need it back. If anyone finds it, please get in touch here; I’d be grateful to recover it.