First of all, if you are using the birth control
pill correctly (taking a pill at the same time every day without missing one) than you have a less than 2% of being pregnant.
More than likely, your missed period
is either from just starting the pill (it can take up to 3 months for your body to adjust and you may have irregular periods
during this time) or from the pill itself. Many low estrogen
formulations can cause very light or even missed periods. Some women will choose a low-estrogen pill just for that side effect! if you continue to have irregular periods past 3 months and fond it worrisome, talk to your doctor about switching to a different pill.
If you have missed pills, have had unprotected sex
and think you might be pregnant, a home pregnancy test
will be 97% accurate 1-2 weeks after the missed/light period. A doctor's urine
test would be able to detect a pregnancy test now. Good luck!