Carry the crystal with you, it seems like a message from hecate - probably. Your spell may have worked in a way that made the crystal 'charged' and I believe that you should carry it on your person from now on until the spell comes into fruition.
This is at least how I interpret this event.
How do you feel about it, what is the first thought of an explanation that popped into your head - not the reasoning and the justification that came after, but the very first assumption that came into your head?
Meditate on it a bit, trust your gut and intuition