If you've gained a significant amount of weight in recent months, this could affect your period's regularity. Women naturally have estrogen that helps make the uterus a comfy and favorable environment to a growing fetus. However, if you're overweight or obese, you might actually accumulate fat cells that produce a form of estrogen called estrone. These cells mimic pregnancy, so that you're not ovulating, but blood continues to line your uterine wall. It builds up to such an extent that when you finally do get your period, it's heavier than normal and it seems as though it'll never end.

Losing even five percent of your body fat can get the menstrual cycle back on track so you can either get pregnant (if that's your goal) or simply have a regular cycle again. This is because the fewer fat cells you have in your body, the less hormones they secrete — which is one of the causes of irregular periods.