My partner and I been trying for a baby for 2 years. She has heavy periods and irregular can that be the cause?

Could be... It is hard to say over the internet that the cause of no pregnancy over a 2 year span is due to the symptoms you describe (but it could be). Infertility is usually defined as not being able to conceive after one year. It would be worthwhile having you and your partner evaluated by a specialist. Many times if something is found, it is treatable. I wish you the best of luck.
Irregular menses. Would suggest evaluation by a gynecologist to address this issue.