THanks for trusting us with your health concern.
A cleanse should not affect your menstrual pattern.
However, what you describe was the breakthrough bleeding
/ slight spotting, which is common while on the pill.
Do not read much into it, unless it occurs frequently, or gets very troublesome.
Minor spotting is common while on the pill.
You can report to a doctor if this persists.
If you are having unprotected sex ( you very well might, while on the pill ) then just take a pregnancy
test if your next period is not on time.
Continue taking the pills as usual without a break.
All the best.