Progesterone question

Got prescribed progesterone on June 19th to take for 10 days to induce a period. I’ve had no bleeding since, until now which is 16-17 days later. It’s been very very light brown/pink spotting, not enough for a pad or anything but visible when wipe. Just confused and wondering if anyone else has experienced that or anything. I did mention it at my last dr appt last week but they were more concerned with doing a full panel blood test for other possible issues.