The sun's activity in form of sun spots changes in a cycle of 11 years, where the activity goes up and down. (skepticalscience.com)
So, I just want you to keep that in the back of your head when you notice changes in your cycle. (ovacue.com)
Being aware of the unique functions of your reproductive organs and when different changes in your cycle occur can help you on your way towards getting pregnant. (pregnancy-info.net)