The best to know if you are pregnant or not is to take a test. With the new pregnancy tests available today detecting a pregnancy can happen much sooner than it used to. You used to have to wait until 1-2 weeks after you missed your period. Now you can test as early as 4-5 days before you miss your period. If you get a negative result and you really think you are pregnant then try again in a few days. The farther along the pregnancy gets the higher the hormone levels get and the more accurate the test will be.