Im a 26yr old, i dnt get my periods regularly the last time i got my periods was in nov2017, took home pregnancy test they can out negative,what could be wrong?

Irregular periods: Severe physical or emotional stress can delay ovulation or cause incomplete ovulation (eggs are not released) which causes polycystic ovarian syndrome (PCOS). Whether you are sexually active or not, oral bcp's can suppress your ovarian function and protect against later infertility and uterine lining growth. Ask your healthcare provider about oral bcp's with your history.