The time when someone with a uterus typically has the highest sex drive, namely ovulation, is also the time that they are most able to get pregnant from PIV. Even if you’ve taken all other contraceptive precautions (condoms, both control, etc), there is still always at least a minuscule chance that those contraceptive measures will fail, so if you want to have sex and really make sure they succeed, the optimal time to prevent conception is during your period. Unfortunately, for many with a uterus, this is also the time that sex drive is lowest, and many people with penises are averse to the idea for one reason or another. However, assuming both partners are willing to have PIV while the uterus-owner is on their period, they’ll be the least likely to get pregnant compared to any other phase of the cycle.
Actually, the “ovulation is the higher libido time” has been, if not disproved, at least contested by large scale studies and surveys. The reality is that hormones and cycles affect each individual differently, and in some cases, more women declared feeling higher level of arousal during periods than during ovulation.
Other than that, the rest of the statement stands ! Of course, while the post does not advocate for it, we emphasize that unprotected sex during period protects from pregnancy but not STDs, and as such should only be practiced with trusted and tested partners.
And also, we advise specialised menstrual cups to make sex during periods easier :)
I can only speak for my own experience with women, and the three that I’ve had sex with during multiple different parts of their menstrual cycle (the three I’ve had relationships with and weren’t ONS’s) had the highest libido during ovulation and the lowest during menstruation. I have no idea how true this is for the general population though.