JoJo had a false pregnancy last year, but she didn't keep us up. She also didn't carry around stuffed toys as you've indicated Morgg has done. She just gained a LOT of weight - and LOOKED pregnant - eventually it went away.
Our first two beagles had false pregnancies. Worst of all was our last one, Spotty, she would also nurse a toy rat and take it everywhere with her. It looked so sweet, but then our vet warned us to take away all soft toys or anything she nursed, as it prolonged the false pregnancy. Later in life she got mammary cancer and it was essential to get her over the false pregnancies as quickly as possible.
it just happens, meg had hers about 10 weeks after her season. the vet said if they get a phantom pregnancy once they are likely to get it again after the next season. they can give drugs to stop it but best if nature takes its course. meg was spayed straight after as its better from them. if not they can go on to get problems with their teats or something. meg wouldnt let us go near her much when she was going through it and would just wonder around with her teddy crying, it was sad to see her. :-(