Did you had regular period before this?
Do you have hot flashes?Are you taking any medications? Any stress or anxiety?
Well, at your age such irregularity can be due to perimenopause, it can result in longer, heavy or missed period . This may take 2-5 yrs, for your body to get transition into menopuase.
You should get a checkup from gynae doctor, and medications can be adviced to get rid of perimenopuase symptoms.
Usually cramping and bloating occurs days before menses, you may have periods, in coming days. also if you are sexually active, it is essential to rule out pregnancy.