Easy does it Paul. I have been through some rough times with my two youngest kids during their birth. My daughter was still born and needed emergency medical treatment to get her to spring into life. She'll hopefully been graduating with a MsC this year. My youngest son caused my wife so much medical trouble that my wife ended up on life support and a blood drip for more than a week after the birth. Both of those kids were born premature.
So a bit later is a good sign of a healthy baby. Someone once told me (it might have been my mother who served in the medical profession as midwife etc.) that babies that are born later tend to be good athletes or have a higher than average IQ. So you could be the lucky father of a future World and Olympic champion, or child genius .