Worried teen that doesn't want to talk to there parents. thinks she could be pregnant. hey so i have recently (friday) just had sex. i am on birth control and the way it works i am supposed to be on my period this week (yesterday) but it has just lightly

First : First of all, good for you for using birth control! depending on the method and how well it is being used, many methods protect more than 90% of the time. However, there is always a small chance of pregnancy with any form of birth control (even getting your tubes tied isn't a guarantee!). You can either take a home pregnancy test as long as it has been 5- 6 weeks since your last normal period, or you can go see your doctor and they can test you. A home pregnancy test is 97% accurate if taken a week or more after the missed period. A blood test can tell if you are pregnant as soon as 7 days after conception and a doctor's urine pregnancy test can tell if you are pregnant around when you next period should come. That being said, there are many reasons for a woman to miss her period: stress, diet, weight loss, excessive exercise, or even a hormone imbalance such as a thyroid disorder or polycystic ovarian syndrome. If you are pregnant, or if you continue to have irregular periods, you should give your doctor a call. Good luck!