What do you do if you hear someone in your house at night?

I got to SO’s house very late the other night; I was literally bleary-eyed & probably should have pulled over somewhere to take a nap. I am both ashamed of my actions & thankful that nothing bad happened - no alcohol was involved, just lack of sleep.
I have a key to her house, & like usual, unlocked & opened the door & made the standard two trips in with my stuff. Adult kid’s bedroom is downstairs & her dog (1½ yo pittie never makes a sound for me at night though he does bark for any noise outside during the day). However, unlike normal I just crashed downstairs; I just couldn’t deal anymore &, very unlike me, couldn’t deal with my 4-legged baby gurl who was upstairs & would be very happy to see me & would demand skritches & kisses; I just needed sleep. However, she heard me, got up off the bed & stood/sat by the door, wagging her tail, waiting patiently for me to come up. SO woke up, too, & took some phone pics/video of her. SO, knowing I was getting there late, hearing noises that coincided with that & seeing the dog’s reaction promptly put her head back down & fell asleep again. My baby gurl was laying by the door thee hours later when SO got up for the bathroom.

I am a horrible, horrible person & really should have pitted myself for disappointing her.

We’ve had that before