Girls, in an hour I'll be at 40 weeks. The midwife said on the appoint…

Girls, in an hour I'll be at 40 weeks. The midwife said on the appointment if I don't give birth by 27, come see her that day for a referral. What will this referral give me? I think it will be a stimulation, right? But pregnancy can last up to 42 weeks, after all. There are no premonitions at all, I hope that maybe it will start overnight, not wanting stimulation ????? Who stimulated like this? Do they differ from the natural process?