I live alone with my children. I am a single mother. My baby is quite difficult ATM and seems to be cluster feeding so I'm always awake quite late. She finally drifted off about an hour ago so I have been cleaning non stop since. Anyway I've been up and down the stairs putting rubbish out etc. anyway I came back upstairs and my door knocked, this was literally 10 mins ago. Obviously I got quite scared due to how late it is. They knocked about 3 times then left. Didn't knock any other doors. I can't be 100% sure but I thought I heard what sounded like a police radio. Would you have answered?! Wibu? I wanna point out now that a few months ago this same thing happened when I was heavily pregnant. I woke up in the middle of the night went toilet came back and lied in bed and my door knocked, it was roughly the same time. I know no one that would knock, or who would just show up.