In our hospital fragmin alone isn't a reason to induce before 40 weeks. There has to be at least one other risk factor before the will schedule induction. They won't let you go over though and schedule induction for a few days past your due date. From what I've heard it varies by the area you live in and hospital you are under. We are given leaflets with our injections that say unless told otherwise by a consultant you will be allowed to go into labour naturally, but to stop injections if you have had a show, are feeling regular contractions or your waters break. It also says to book an anethestist appointment to discuss pain relief as an epidural may not be possible if you are in labour but have had an injection less than 8 hours before.