Fifty percent of the total mass of the atmosphere is located in the lower 5.6 km (18,000 ft) of the troposphere. It is primarily composed of nitrogen (78%) and oxygen (21%) with only small concentrations of other trace gases.
Having irregular periods is very common. I see them in my practice all the time. The causes can range from something insignificant to something that requires treatment. For example, if you're a teen, your body's hormones can fluctuate and take some time until they find a balance.
Follow us. For sexually active women, irregular periods can be an immense source of anxiety. Many will immediately wonder if an abnormal period is a sign of pregnancy  a loaded question if becoming pregnant isn't planned.Other women who look forward to having a family can be alarmed that irregular periods signal a complication with their fertility.hough unlikely, irregular periods could be a sign of a serious health complication, such as polycystic ovarian syndrome, thyroid dysfunction, polyps, or cancer. It is a good idea to see your doctor to rule out any underlying causes.