What Does The Absence Of Bleeding After Taking Nordette Indicate?

hi. A question on when is might be the soonest that i can do a pregnancy test. i had an unprotected sex last Nov. 26 and took Nordette as ECP 3hours after the deed, and another dose after 12 hours. I ve tried Nordette before and had withdrawal bleeding 7days later. So, i was expecting the same effect but i m on my 10th day sunce and still no bleeding. i took a pregnancy test yesterday and it came out negtive. Is that accurate? Is it not too early for a PT? please help. Thanks.