I've just found out I'm pregnant after trying to convince since August 2015. I was using the contraceptive implant and my cycles lasted for 23 days (not sure if this makes a difference) my last period started on 14th October and according to a chart on here my due date should be July 21st 2016 but I'm confused as I'm not sure if the length of a cycle makes any difference as I never had a normal 28 day cycle