I had permanent makeup eyebrows done three days ago. The scabs are coming off.

Hello and thank you for your question.
That is correct. You want the area to heal before any corrections can be done. Sounds like the scabbing pulled your pigment right out. At your touch up visit your artist will modify the color and correct the area. 
Hope this helps,

Hi farley97,Typically, the scabs fall off between 5-7 days, but it's okay to fall off earlier. On the 8th-10th day, it can look worse since your brows might look like they are "disappearing" or fading fast - yours is just ealry. By the 14th-28th days, the brows start reappearing. You'll also see hair regrowth at this point. 
Corrections are done in the next session so make sure that you make your microblade perfection session.All the best, Justin Harper, M.D.