Hello, 
Morning after pill taken within 72 hours is very effective to prevent the pregnancy. 
This can however, delay the periods by 10 to 15 days. 
Get the blood test done to ascertain the pregnancy as it is already more than 15 days late and there are always chances of failure after the use of this pill. 
Consult your doctor and get yourself checked up and evaluated properly. 
Thanks 

hii rubenpowell
kindly do urine pregnancy test of her.... kit is available in any chemist shop, which is easy to perform..which could give confirmatory findings regarding pregnancy... as she had taken unwanted 72 within 10 hours of sex.... there are very less chances but still contracepetive failures could occur... do not wait for so long time...
about your last query... yes emergency contraceptives like unwanted 72 could prolong the periods in few cases...
one sincere advice always have safe sex... don't depend on condoms only... kindly avoid sex during unsafe period and if at all you are having it use spermicidal jelly along with condoms...
do not panic... take care...

Hi,

Thanks for your query,

Unwanted 72 prevents ovulation or if taken after ovulation prevents transport of sperm and egg. If you have taken the pill within 72 hours of unprotected sex, you are protected against the pregnancy. Its success rate is around 91 to 93 % as reported, So the chances of pregnancy is quite low. But i will suggest you to go for a pregnancy test for further confirmation. There may be skipping of periods or irregular periods due to harmonal pill intake.

Best of luck and take care..

Hope it helps you..