Is this normal bleeding on birth control?

I have been taking the active pills only, since the beginning of the summer. I had an appointment with my fertility specialist this past Thursday and mentioned that after my first pack, I started having some red bleeding (middle of July, like spotting or light period) followed by brown spotting ever since. She just said it was breakthrough bleeding and not to worry. Then Thrusday night after my appointment, I started having red bleeding. It has been like a light period since. Since I'm not taking the sugar pills, I should not be getting actual periods.

Here's my issue, she is supposed to tell me today if i can stop the birth control, wait for my period to start, and then start medication to hopefully get pregnant. What I'm concerned about is if I continue having this bleeding, I won't know when my period actually starts and I won't be able to start the medication on the right day.