Most women have a regular menstrual cycle. This means they can predict fairly accurately when the next period is expected. Some will have irregular periods for various reasons. Still, regular periods could change into an irregular pattern, causing a bit of anxiety. Regular periods imply regular ovulation, and high chances of conception. Irregular periods on the other hand imply unpredictable ovulation patterns, and often a delay in conception.
Continuous surveillance is not just valuable in entertainment, it is ubiquitous in the security industry. But less obvious adaptation of surveillance has always played a role in aviation safety. The so called black boxes are a mandatory requirement in commercial aircraft. They record all the flight performance data and cockpit conversations, which later become useful for investigations of aviation incidents and accidents. You can term it as a form of Big Brother, continuously recording events, albeit for safety reasons. And now, the healthcare industry is adapting continuous surveillance in attempts to reduce medical errors and improve overall healthcare safety.
Modern medical care, largely based on the science of disease, is what currently defines conventional healthcare. But non-conventional medical care has always had its place and includes complementary medicine, alternative medicine and integrative medicine. When non-mainstream healthcare is used together with conventional medicine, it's considered "complementary". And when a non-mainstream practice is used instead of conventional medicine, it's considered "alternative". Integrative care involves bringing complementary and alternative approaches together in a coordinated manner.
General health calculators are mostly linked to lifestyles. The commonly used ones are related to weight. You can calculate your body mass index (BMI for short), amount of calories burned during a work-out, or calories ingested with certain meals. You can also calculate how much of your body is actually fat, how much you need to eat daily to maintain health, how much alcohol gets into your blood during a drinking spell, or how much physical activity is needed to raise your heart rate to a certain level.