I think primarily the pain will lessn and go away for a consecutive two-week period, but even two weeks can be too soon to tell. It takes the fissure 6 -8 weeks to actually heal. There is no reliable sign, from what I've seen. It's what drives us all crazy...you can have several good days and suddenly be back at square one again.
Sort of having a Dr. examine you and pronounce that it's healing, it is hard to tell. Long-term absence of symptoms., beyond two weeks. That is my best guess.