What Causes Irregular Periods?

gud mrg sir i m lakshmi,age 25,height 5.2,weight 50 kg,80 days before i get married,from the age attend i have regular mention&for past 2 mnth also having regular mention,but this mnth the mention came within 14 days(this mnth i having some mental worries).so next mnth is it getting regular or is it contiue 14 days once?if it contiue how can i get the pregnancy?pls give the soln sir,really igetting the confusion.thank you