39 weeks pregnant stomach has shrunk and got constant cramping?

I woke up this morning and my stomach has dramatically shrunk!! its about half the size it was I look like i did at 4 months... also since last night been having irregular contractions and constant nausea... I am 39 weeks and due this friday so Im just waiting it out now also been having alot of watery discharge and alot of craming this morning which I havent timed as they ae not yet all painfull?? does this make a difference?? this is my first so still learning all the signs thanks for your help.. and id just like to say im not concerned it will happen when it happens and my midwife not concerned she is 3/5 engaged and midwife said do what you have to do lol!!!