Mystery Smell

So yesterday morning I got up with the kids and went down stairs and thought that's an odd smell. Changed diapers, looked for bottles left laying around, and did the dishes. Still not getting any better. I have to say so sorry to Jamie Jones who came over for a meeting and I am so surprised she didn't puke on my floor being pregnant and all, cause I know that if I was pregnant I would have puked on my own floor. So I thought someone needs a bath. Did baths still not getting any better. So I had to wait for Colton to get home because I have a bit of a cold and my sniffer isn't all that great. He walks in the door and say "WHAT IS THAT SMELL" I knew it was bad but not that bad. So we started sniffing around and finally started moving furniture and we found a spot under the couch that smelt very sour. We shampooed the whole carpet asap. Still so smelly. We cannot figure out what happend and so I guess for Christmas we are getting NEW CARPET. Not exactly what we wanted but what can ya do.