As Neils Bohr showed, it is possible for electrons to move between energy levels. Light contains energy. If a photon of light strikes an atom, it is possible for the energy in the light ray to be transferred to one of the low energy electrons moving around the atomic center.
Spotting before a period is due â reasons for spotting before a period can be implantation, from a cyst or a short luteal phase and impaired egg quality. Spotting in between cycles â this is a difficult term to answer but often means your cycles are growing shorter; often with perimenopause.
To reproduce. Your period is caused by the shedding of the uterine lining when there was no fertilized egg to attach to it. Your body gets rid of that lining. That is your period. That is also the reason why you don't get a period when you are pregnant as the body won't shed the lining since there is a baby implanted in your uterus