I'm 37 weeks and woke up last night in a big puddle. Obviously thought my waters had gone (thankfully had put a huge pad under the sheet last week) but the midwife is fairly certain that no, I just wet the bed. How mortifying!! 
Apparently it's not unusual at this stage but I'm not convinced. DH is laughing with me about it but I'm still horrified that he'll always know this now.