I guarantee you, even without drugs your pregnancy will not go on forever.
I don't know your situation, but I know that "low amniotic fluid" and "deteriorating placenta" are terms that doctors make up to scare women into accepting Pitocin. If it wasn't safe for a fetus to remain in the uterus, the body would get it out of there. If the baby isn't ready to come out yet, the body keeps it in.
If you have a midwife, I'm sure she will be glad to check the heart rate if you are worried. If you don't have one, you may be able to check it yourself with certain devices. If you are seeing an OB, if you refuse to be induced they will want to check the heart rate anyway. Be sure you can hear it yourself, so you can count the heartbeats and won't have to just accept the answer they give you. (Also, true fetal distress is not confirmed by heart rate alone, and different practices have different "acceptable" heart rates...)
Are you sure of your due date? U/S is not very accurate at predicting it.
If you really believe you have a problem with amniotic fluid, you could try walking, sex, breast pump, and other non-invasive, natural means of induction.