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.
A Patricia Geraghty, NP , Women's Health, answered. Losing one ovary, as long as the remaining ovary is healthy, should not cause irregular periods. The control of our menstrual cycles is a result of the communication between the brain and ovaries. The messengers are our hormones which are transported in the blood throughout the whole body.