After reading through the first page of that thread, I think I must have had very low progesterone up until my implant ran out as the progestogen would have lowered my blood levels of progesterone.
So I think my body is responding to a rise in progesterone now the progestogen is gone. Could this account for the rapid growth I've seen in the last two months? Or am I misunderstanding things? (I never know whether I've made the correct conclusions)