Is Dark Spotting 2 Days Before My Expected Period After An HSG Procedure Normal?

Good evening Doc, i had hsg on d 9th of jan n i had my last period starting 31st Dec n ended 2nd January, bt my next period was supposed to be due on 26th of January been 27days circle. Bt since 24th night been having dark spotting, bt today 25th it was a bit much very dark. I don t know wat it means