I know from experience Irregular periods can be inconvenient, but there are common causes and simple like Polycystic ovarian syndrome (PCOS), infections like endometriosis, uterine polyps and fibroids; low thyroid function. It can also be as a result of prolonged antibiotic use, or even some family planning. You can normalise your cycle by getting treatment to infections, Reduce body fat through diet and exercise , Manage stress or maybe Try yoga