It's not an ink stain. As @scottyg mentioned, tattooing creates an open wound. In the course of the healing process, a scab forms, much like it does for any other wound. This scab will usually be the same colour as the ink. As the healing process progresses, it gradually flakes off.
Scabbing usually takes place within 2-3 days but the peeling/flaking off part can take 2-3 weeks or even longer depending on a whole lot of variables.
Just keep it dry and clean and try not to scratch, peel or pull off the scabs or flaking bits. If it gets too dry, a little unscented moisturiser should help to prevent it from cracking. But you should seriously follow the advice of your tattoo artist with regards to aftercare.