In general, many women will have some spotting or breakthrough bleeding while on an oral contraceptive. This may be what you experienced. However, it is also possible that you may have become pregnant while on the pill because no method of birth control other than complete abstinence is 100% effective, so it is important to discuss your concern with your doctor
bleeding from pregnancy does not typically last for a week, so this bleeding you mentioned may be completely unrelated to the possibility of pregnancy. But, if you have had any irregularity with taking your pills, in some cases even varying the time at which you take the pill by as little as an hour, then it is certainly possible that you could be pregnant. Overall, to protect your health and make sure that the bleeding you experienced was nothing of concern, the best thing for you to do is make arrangements to see your primary care physician
or your OB/GYN as soon as possible. Your doctor can go over any new symptoms you may have developed while on the pill as well as do a pregnancy test to make sure that you aren't pregnant. If you have recently had sex with a new partner without using barrier protection, it may also be important to test for other sexually transmitted diseases.