If you are not married and not having any physical contact, you should get your periods soon. you can take meprate/deviry tablets 10 mg bd for 5 days, following which you will have withdrawal bleeding. Also plz mention what is your weight. Do regular exercise. Also go for one
Thyroid profile test. Although one single episode of delayed period is not of concern, but If you are overweight, or having some problems like acne or hirsutism, consider PCOD and go for thorough check up.