I'm on birth control (pill) and my period is a day late. have been stressed the last two months period was light last month. how soon should i test.

1 week after misssed: period is the most reliable, but if urine is concentrated, such as first morning urine, some tests will give a postive result as soon as first day menses are due but a negative test may still be unreliable. Stress can definitely affect menses and If you have been taking your bcpills regularly, then risk is very low.

Anytime: It is unlikely that you are pregnant if you have been taking your pill regularly and on time, however you can do a PG test at any time at this point in your cycle.

Pregnancy test: A pregnancy test done a week after the missed period should be accurate.