Water randomly just came out of my shower drain?
I was sitting in my room when I heard a gurgling sound, so I ran to my bathroom and saw my shower drain was pumping out murky water with brown chunks in it. After probably 30 seconds it stopped, and a few minutes later the water drained away. I sniffed the air above the water when it was there and it didn't smell like sewage or anything, but it certainly looked gross. I haven't touched my toilet, shower, or sink for a couple of hours, I think 4? My room is connected to the back of somebody's house though, so I suppose that they could have recently flushed a toilet or something, but I don't know if my pipes are connected to their's (I can't flush toilet paper down my toilet because it's electric or something, but I know that they can flush paper in their house). This is probably the third time that I have been around to hear this happen, and I think it started around a month ago? Can someone please tell me what is happening here?