Do I still take provera ???

So I’ve recently been diagnosed with pcos so my obgyn prescribed me provera to take every 21 days to start my period and I’m suppose to start my first round on the 20th after my ultrasound but I started spotting pink yesterday and now it’s slightly heavier brown and little streaks of red so I’m pretty sure it’s the start of af . If af does officially come I don’t take the provera right ?? And if it’s stays just spotting should I still take it ?? I’m gonna try calling my obgyn tomorrow and ask but everytime I’ve called in the past for a medical question they always tell me they will have someone call be back and they never do I even call for the same thing multiple times and they never call me to answer my questions so I end up having to use this app and google to make my own educated decision.