I am 22 years old and have been married for 3 1/2 years and i am trying very hard to get pregrant.i have irregular and heavy periods..?

U need evaluation: U need to see your obgyn, as that is not normal, at yoru age you should have been able to get preg in 12 months, most likely u are not ovulating so u will need help, you need an exam, blood work and an ultrasound and u may be a candidate for oral Clomid (clomiphene) or you may need fertilty shots.

PCO: It can be a sign of poly cystic ovary.Also most common cause of infertility is due to male factor, hence both you and your partner needs evaluation.