It turns out that this could become a possibility. Centuries before the oral contraceptive pill was approved in 1960, women tried all sorts of methods to prevent unwanted pregnancy. Staunch supporters of modern medicine (only) like to point and laugh at use of crocodile dung and cat testicles, but there were much more pleasant remedies around. One of these is the thunder god vine, also known as Tripterygium wilfordii in scientific circles. In a research article published on the 15th of May, 2017, scientists at the University of California describe exactly how two phytochemicals present in the medicinal herb can prevent fertilisation.
|Cycle tracking beads. Source: Dellex.|
There are also other forms of "natural family planning", such as the Billings ovulation method, which are free of side effects, but may be less reliable. In a small study, 15 Turkish women monitored their fertility across 30 menstrual cycles using both the Billings method and urinary levels of luteinising hormone (LH), which spikes during ovulation. The Billings method detected a potentially fertile period of 10 days, with a "peak" in the cervical mucus sign on day 13 (as an average, day 13.65). The surge of LH that accompanies ovulation also peaked on day 13 (as an average, day 13.65), and lasted for five days. This association was deemed significant, and it was concluded that women can use this method effectively. However, it is a small study, and every woman is different. According to the World Health Organisation (1981, sourced from Wikipedia), this method is at least 97% effective with "perfect use", and 77-99% effective with "typical use". In other words, it seems best to stick to the Billings method's precise rules, and probably use a condom as well. So, in conclusion, you don't have to put up with birth control side effects just because you were born as an opposite sex-attracted woman. However, you do need the correct training to use natural family planning methods, and will probably have to wait several years for proven herbal methods. This article is not intended to be birth control training or advice, it is just for general information.