Took Diane 35 After Unprotected Sex. Noticed Brownish Discharge. Is This Normal?

Hello there! My girlfriend and I had unprotected sex last November 10. That was also the first day she took a pill of Diane 35. I did not release inside and just had a withdrawal. 12 hours after she took Nordette and stopped taking Diane 35, since she didn t want to make it complicated. A week after, November 18, she had a brownish discharge for 2 days. Is this normal? She apparently forgot when her monthly period comes, but it is pretty normal. Anyway, is it safe to start drinking Diane 35 again? Thank you!