It is my experience that the converse has been true. A number of my students over the years have come to class after having tried unsuccessfully to conceive. And then have become successful with a regular Bikram practice.
I did look at the site that you recommended. It quotes all the good reasons to do yoga. They particularly note the ability to reduce stress is “extremely” important in addition to all the body toning effects etc. They mention in passing the ability of yoga to balance hormones.
I believe strongly that this balancing of hormonal systems occurs more efficiently with the Bikram system. Not just because of the heat, but there is the potential for more profound effects to be facilitated by practising the series in the heat, along with the positive effects of connection in the mirror.
They do quote an unreferenced study about how those practising yoga were twice as likely to get pregnant.
Then without any evidence at all they offer you an OPINION. That they don’t advise people to do Hot Yoga. It is MY belief that most opinions about Hot Yoga are usually unfounded, based on ignorance and fear. Remember: that statement on that website is simply someone’s opinion.
I cannot promise you that you will become pregnant - nobody can. But stacking the odds in your favor is what you need to do. Don’t you find this yoga the most immensely satisfying experience? That has to go towards reducing stress in a major way. Add that to the mirror, the heat and the physical benefits and you have an alchemy that can and often does produce miracles.