Thank you for sharing your question with the EmpowHER community.
It is normal to experience irregular periods after a C-Section but usually it has to do with light, spotting or no bleeding. It is really hard to say or speculate. Perhaps your doctor want to give it more time.
How long have you been taking the birth control pills?
You may need more time for your hormones to adjust to the birth control pills. The adjustment period can be anywhere from 1- 4 months before things start settling down.
I hope this helps.