how long before you know your pregnant
The obvious signs of pregnancy occur about 2-4 weeks after conception. Some signs like vomiting or morning sickness. By this time you can a pregnancy test will also now be able to identify if you are pregnant or not. Follow this link for more: http://ezinearticles.com/?Pregnancy-Symptoms-and-Signs&id=70487
One can usually tell if they are pregnant 1 week or so after their first missed period. A blood test through a hospital will detect pregnancy 1 day after a missed period.
There are some pregnancy tests that say you can take them as early as 5 days before your period is due. Most women will wait until their period is late to take a pregnancy test because if you take them to early it may give a correct result.
Typically most women will have an idea that they are pregnant after the first missed period. At this point it is wise to test.
A woman will not know that she is pregnant until her first missed period. A woman can take an at-home pregnancy test sooner than her first missed period, but sometimes it will give false negatives.
A woman should approximately wait for 10-19 days after having unprotected sex. Then afterwards she should have a pregnancy test to confirm if she's pregnant or not.