Hello,
If you are taking the birth control pills for the first time, then it may take atleast 3 months for the birth control pills to be effective. If you miss your periods then I suggest you to test for pregnancy by a highly sensitive pregnancy test 10 days post ovulation with a sensitive ( 20 - 25 mIU ) pregnancy test. Also then I would suggest you to get your serum HCG levels estimated since this is more specific than urine for pregnancy tests.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.
I was told by doctor tat it takes 3 months for the pill to fully protect u from pregnancy. i was on the microlite pill for 5 years and recently got off it to try for a baby.. i used condoms for the first 3 months and didnt fall pregnant once while taking the pill once u take it at the same time each day and be careful if your on any other medicine it took affect it..:)