I missed my periods from 17 days after have a unprotected sex now someone said me to take gynaecosid and rotec to get periods?

Can do PregnancyTest: Pregnancy is the most common cause of a missed period. If not pregnant, other causes of a late or missed period include: excessive weight loss or weight gain, increased exercising, emotional stress, having an illness, traveling, medicines (especially birth control pills), hormonal disorders, etc… A visit to one's doctor is a good idea if the next period is also missed, or if worrying too often.