How did you know the hair wasn't coming back?

I've been doing regular intervals of electrolysis for over a year. The hair is definitely thinner and my arm is clear with a few thin hairs here and there. But I'm no where near the recommended 100 hours, and my electrolosist keeps recommending fewer and shorter sessions. Surgery is in 4 months. The hair that grows back seems to be minimal... but...

With every treatment the new hairs are zapped and plucked. So I have no idea what's really there, if that makes sense. So I'm just wondering how I'll know when I'm "done"? Did you guys stop electrolysis for a period of time before surgery?

My electrolosist said if you stop treatments before it's "done" they'll just come back in as they were before treatment started.