Hello, Thank you for asking your query at DoctorSpring.

First thing you need to understand is every women metabolism is different, therefore even menstrual cycle will vary. But, usually most of the women start their period in the placebo week or free pill week. As this is the first time you are using a pill, you may just spot or may not have a period at all. Your body system takes 3 months or more to adjust to the hormones. Therefore, after usage of 3-4 weeks you will be able to predict when you can expect your period.

When you are taking birth control pills, you are protected the entire month if you have taken the pills correctly. Therefore, I don't see any reason for you to worry. There are very less chances you can be pregnant. You can try doing the Urine Pregnancy test, if you are very worried.

Hope this helps. Please feel free to ask follow-up questions.