hello...
thanks for trusting the health care magic doctors for ur health related queries.
first of all i want to tell you that
pregnancy can happen after taking
emergency contraceptive pill, if it's taken by wrong method.
usually emergency contraceptive pill
levonorgestrel 0.75 is taken within 72 hours of unprotected sex and 2nd tab will taken after 12 hours of 1st tab, in this method it is more effective.
but u had took 2nd dose after 48 hours of the first tab, but ur pregnancy test comes negative twice, it indicates that u r not pregnant, so don't worry.. relax.
with the above discussion u can try out my suggestions-
1. wait for the menses to come. if it came then nothing to worry.
2. if menses not came then visit nearby gynecologist. he /she can help you.
good luck.
regards- Dr sudha rani panagar