What Causes Delay In Periods?

sir, i had never hed sex with my girlfrien. her hymen is still intact. it just happened four days ago that i had inserted only the tip of my penis inside her. i had not ejaculated within hours(to be presice 10 hours) and nor inside her. but sir she was supposed to be having her periods day before yesterday,but she has not yet started. sir i have fingered her once or twice,but can she be pregnant? if yes then what can we do now? what pills or other methods are available in India?