I ditto what Emilily said I am in the same position as her now a year down the road only more like every 6 weeks for appointments, no more dark / black hairs.
You are just starting out and realising that what you thought were the same hairs you were plucking over and over were in fact different hairs.
No hair grows back within a week, stick with it hun if you have a good electrolysis you’ll be rid of them soon it took till 8 months for me to be rid of the dark ones.