Roommates: did I cross a line?!

Okay so my boyfriend and I live with another couple. Things have been kinda rocky lately between the two of us (the two couples that is). Well we are never home on weekends. And the washer and dryer hookups and everything are in their room. I'm suppose to do laundry on Monday (tomorrow) but between college classes and work, it's hard to catch up from all week. And I try to finish ALL our laundry before the other girlfriend gets home from work on Mondays. Well the roommates weren't home tonight so I went to go put in a load before bed. As soon as I started loading the washer, they walked in their room as they had just gotten home.  Was I wrong for going in their room while they aren't home, to start laundry so I can have it all done in one day so they can wash clothes all week? Or am I overthinking it? Should I apologize? I really don't want to step on any toes or make anyone mad. And I wasn't trying to invade their space.