Female biology may not be rocket science, but keeping track of menstrual calendars is not always the easiest thing either. Raise your hand if you agree with me, or so asked the tech world before plunging itself headlong into a field now termed ‘femtech’. Femtech, in simpler words, is an assertion that the female reproductive system is often a complex, moody thing and technological assistance can go a long way in helping us understand it.Consider exhibit A - a paid mobile application called Natural Cycles. Developed by a former CERN physicist Elina Berglund, it claims to be “highly accurate” when it comes to preventing pregnancies.App stores are flooded with several apps of this kind which track a woman’s reproductive cycle, helping her understand when she is most fertile and otherwise, to map her sexual activity accordingly. All of them together form the realm of digital contraception.Yes, contraception is no longer limited to a pill or an external tool, but now apparently is also constituted by technology. Why I specifically mention Natural Cycles is because it is approved by the US Food and Drug Administration (FDA). It is also the only app of its kind which is certified as contraception, according to The Guardian. Earlier this year, the app was in news because several women who had been using it found themselves in that one situation they were using it to avoid - pregnancy.The international backlash against Natural Cycles took the form of medical investigation in Sweden, and a general questioning of this whole idea of femtech, an industry expecting to be a 50 billion-dollar-industry by 2025, according to this report.Let’s Talk Ovulation, Your ‘Fertility Window’ and Making BabiesThe app has a user manual available in 13 different languages. But if you’re not feeling up for going through it, here’s how it works. Every morning when you wake up, you have to enter your body temperature first thing. Along with this, you also have to regularly enter your menstrual cycle details. Based on this, the app figures out which are your most fertile days, and marks them in red, which means the chance of pregnancy is extremely high during those days.Other days are marked in green, suggesting that you can go ahead and have unprotected sex around that time. However, the fine print of the Natural Cycles mentions that it’s accurate for only up to a 93 percent. What happens to the remaining 7 percent? You guessed it right - pregnancy. But we’ll come back to that bit later.There is also no protection from STDs and STIs when you use Natural Cycles (or any other app of this kind). Again, this is mentioned on the site, but it’s not hard to miss in the novelty of digital contraception or an app that promises to take you off the pill.In addition to all this, there is also a questionnaire you’ve to answer before your subscription. It’s made up of questions about your body's sexual and reproductive health and asks for a time period of a few cycles before being able to assess you in its entirety.#LetsTalkFertility: Could Egg Freezing Be Your Answer, Ladies?You’re most likely to get pregnant a day or two before you begin to ovulate. There is actually a six day window right before ovulation, along with the ovulation day itself, which offers a good chance of pregnancy.That is not to say women can’t get pregnant otherwise. Women can get pregnant even during their period. But the timeline around ovulation is your most likely window.The first day of your menstruation is also the first day of your menstrual cycle. The last day is the last day before the next period. Ovulation happens 14 days before your next period if you have an average 28-day cycle. However, it varies from person to person, even for women with regular menstrual cycles.The chances of pregnancy increases by 27-33 percent in the three days leading to ovulation and decline rapidly immediately after, according to Fertility Coalition, Australia.For many women, who have a 28-30-day cycle, the fertile period starts from the 10th day from the first day of their periods.Dr Monika Wadhawan, Senior Consultant, Department of Obstetrics and Gyneacology, Fortis Hospital NoidaBreaking Down Your Menstruation:In January 2018, a major Swedish hospital concluded that out of the 668 abortions that took place between September and December 2017, 37 were women who had been using Natural Cycles. Following this, the Medical Products Agency of Sweden began its investigation and said that the failure rate of the app was consistent with the claims the app. They claim their failure rate to be around 6.9 percent. This roughly means that 7 out of every 100 women who use the app will get pregnant.Along with this formal investigation, several women have come forward to talk about how the app failed them, and the toll an unplanned pregnancy took on their lives.Other than these general guidelines, the particular problem with apps like Natural Cycles and other period trackers used by women globally and posit themselves as digital contraception, overlook the fact that the consumer might not always be using the app correctly. They also do not account for women with unpredictable menstrual cycles and problems of the reproductive system.You Can Have Sex on Your Period, But You Can Also Get PregnantBeyond digital contraception, femtech is a thriving field currently made up of about 200 startups worldwide, with several of them headed by women CEOs. Woman developers are also looking at it as a source of fighting the lack of women in similar fields, as well as taboo and stigma around issues of women’s health.While it may hold great promise, it’s also important to remember that no contraception guarantees 100 percent safety. While you can rely on age-old, tried and trusted methods of contraception, but at the end of the day, it is the female body and its internal processes which are the boss. So, don’t fall for everything you read online and always consult a doctor before trying health apps.