There are various ideas, the mother, the father, the baby etc... I am 39+3 with no.4. My other 3 were all induced at 3/52 overdue. This baby has a different father, his first and I am determined to not be induced, I have even booked a homebirth (positive thinking)!
Do you think different genes can make a difference? I am 38, its no.4 surely it should fall out? With each pregnancy I have tried everything...........
There has been some research to show that its down to the father - mums who have children with one man and then go on to have children with another tend to go into labour on different dates when compared with mums where the father is the same.
So in your situation - yes! Could well be earlier and if not you can just blame him!!