Brief Answer:
You may likely to be having irregular bleeding

Detailed Answer:
Hello, I'm Dr. Branch,
Thanks for using 'Ask A Doctor' service.

Starting birth control in the middle of your cycle will interrupt its natural rhythm, and will likely cause irregular bleeding. Since your endometrium is already ready to shed, the birth control will likely delay that process, though you may have some spotting over the next couple of weeks, and it may take a month or two for your cycle to adjust completely to the birth control.

So, if you are wanting to delay your period, the birth control may do that.
If you are wanting to start birth control without any irregular bleeding, starting on the first day of your cycle (first day of your period) is recommended.

I hope that helps, please let me know if you have any other questions and I would be glad to discuss it further with you.

Regards

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