If you are pregnant, a pregnancy test at the time that you think that you should normally have your period will usually be able to tell you if you are pregnant. If your periods are irregular, it is somewhat more difficult, but an estimate of when you think you should have your period is usually sufficient. In short, if you are asking the question because you think that the time has passed and you have not had your period, using a home pregnancy test can be effective, and is usually right. If you are trying to know even a few days early, visiting your primary care doctor
or obstetrician does offer the opportunity to utilize an even more correct and earlier blood test that can give a definitive answer.
If you think you might be pregnant or might get pregnant soon, please remember to avoid alcohol and tobacco, and take a prenatal vitamin. Also, please speak with your obstetrician to see if there is anything else that you need to do to optimally prepare to conceive a child. Some women will start to have symptoms of pregnancy within a couple of weeks of becoming pregnant.