Urge to replace front door help

I have bad ocd and my parents put a Father’s Day envlope though the door with money but I fear she pulled it out the bin. Years ago she use to take newspapers out wheelie bin so I have feared it’s been in the bin. My fear with the bin is she put blocked toilet bags in the bin so toilet germs could hit bin. She says she never put it in bin but I can’t clarify she could be telling lies and I may have to replace front door!

I fear everyone coming via letter box is dirty