By that, I mean I change my sheets the next day after sex. It doesn't matter where I am in my laundry schedule iyswim?
Also, in summer, I change them more regularly.
I don't understand why people would do once a week/month and not consider what has happened to those sheets in between.
I will leave them a bit longer if we've had a dry spell(!) so I'm not like a clean freak or anything 