Accuracy of EDD

1st Child- EDD: 16/10 DOB: 4/10 Induced at 38 wks due to back labour pains but cervix was stuck at 4cm. 2nd Child EDD: 21/5 DOB: 21/5 Delivered on EDD. Waterbag was empty by the time I reached hospital so had to deliver. 3rd Child: (Just Delivered this yr!) EDD: 15/2 DOB: 11/2 Waterbag burst while on the way to hospital for check up. straight to delivery ward.