Correct, yet, coincidence and synchronicity are actually synonyms. Through general misuse, many people believe that coincidence means happenstance. The dictionary defines coincidence:
Noteworthy event, circumstance, or series of such, which occurs in conjunction, or synchronously, with others, and is of such a character as to suggest a connection of cause and effect, although apparently no connection of the kind exists.
I started a pub, ChannSpirations and Coincidences, in which we "celebrate synchronicities and the every-person-portal." Diana and Anthi Psomiadou, a frequent contributor to KTHT are my co-editors. They each published brilliant pieces of their own in C&C recently.
Here is my story discussing the concepts and the pub in detail.
LMK if you would like me to add you as a writer.