It's very common for a pregnancy to fail before you're even sure you're pregnant. I'm about 99% sure I miscarried in the first couple of weeks of a pregnancy - and friends have told me they've had similar experiences, especially with their first pregnancies.
From wikipedia: The National Institutes of Health report that "around half of all fertilized eggs die and are lost (aborted) spontaneously, usually before the woman knows she is pregnant"
I don't know if that's what happened to you or not. I'd wait a little while and then do another pregnancy test. If you do go to your doctor ask her what she thinks about 'conceive easy'.