Some pregnancy tests claim they are able to detect pregnancy as early as six days after ovulation, although it is more likely that they will not work till closer to 14 days after an egg has been fertilized. Although you can certainly try a home pregnancy test after only a week or two a negative result may not be 100% accurate. Your best bet is to wait until you should be having your next period and then take the test.
If you are desperate to know if you’re pregnant, and suspect that you indeed are pregnant, visit a pharmacist and ask them to suggest a brand that is reliable.
This site will provide you with some additional information.
http://www.babyhopes.com/articles/howsoonpregnancytest.html