Greetings.
The Yaz birth control pills (or as a matter any birth control pill) when started, do give breakthrough bleeding or irregular periods in fraction of women. This sometimes can continue for 3-6 months in some women. This is not problematic and one needs to continue the pills regularly as scheduled, and usually in most of the women the irregularity or breakthrough bleeding stops in 3 months, so hopefully she should be regular from next month onwards. Please read this resource (see the side effect section in which irregular periods are mentioned);
http://www.yaz-us.com/home.jsp
Please feel free for your follow up questions.
Dr. Arun
Hello,
She is unlikely to be pregnant and the irregularity is quite common as I mentioned. So no worry on that count.
It is pleasure and privilege assisting you.
Doctor (MD)
MBBS, MS (General Surgery), Post-doctoral Fellowship in Sports Medicine