Dear Practo User,
First of all do
pregnancy test at home, if it is positive , visit gynaecologist immediately.
Second , if it is negative then wait for at least 7 days from your expected period date and repeat it , irrespective of result if you do not get your menses meanwhile, visit a Gynaecologist.
Health Tips
She can use precaution in the form of pills / injections /intra uterine devices, if you don't want to use barrier contraceptive .
In case of emergencies like unsafe intercourse, i- pill should b used within 72 hrs, (but not to b taken repeatedly) There is no way to avoid pregnancy later than this.