I'm a whacky statistic as both my girls came before their 'EDD'. My cycles are regular 28-29 days too.

DD1 arrived at 38+5 and DD2 at 38+4.

I had SROM at home with both girls and quick labours. DD1 was 7.5 hours of established labour (I had about 1.5 hours of dull period type pain before my waters broke). I had a dull back ache with DD2 but only a couple of contractions before established labour and then it was only 37 minutes before she arrived!