Irregular menstrual cycle. Next step?

My friend had an unprotected sexual intercourse on dated 27 July 2016.She took ipill d nxt day,I.e.28 July 2016,but after 5 minutes of taking ipill she vomited very less.She is not sure wether she must hv thrown out I pill.den on dated 30-7-16 she did a Urinary pregnancy test which was negative.She is suffering with Pcod and irregular menstruations too.She got her periods last in mnth of May.She missed it in June and July.As the Hcg levels are high in the body only aftr 2-3 weeks of sex,and urinary pregnancy test is more accurate when done at dis time.Is der any chance that she is pregnant?Only back ache she is suffering wid as she is lso diagnosed wid Intervertebral disc collapse.and no other symptoms is seen.And does she need to do a thyroid test coz she has gained a sudden weigh in past three mnths from 73 to 80 kgs.If at all der are chances of her being pregnant what is d accurate way to test and know about it.And what shud b her next step?