(Headcanon by: @bird-ly)
A beta heat/present headcanon I have is that it all depends on their genes:
A BA (Beta gene carrier of Alpha gene) has milder ruts and milder wallowing be a part of their heat cycle. When first presenting they get aggressive and possessive for a couple of days, with Alpha-like levels of rut and wallowing. Of course, the aggressiveness may stay, depending on the person.
A BO (Beta gene carrier of Omega gene) has cramps, sore limbs, headaches and backaches, coupled with mild nesting and irritability - all rather alike the one of an Omega, but with milder symptoms. Of course, intensity and symptoms depends on the person. When first presenting these symptoms are elevated to omega-like levels. BOs have their heat cycle coincide with their menstrual/estrous cycle, male BOs have their heat/estrous cycle lessened, grandiosely so compared to omegas and mildly so compared to their female counterparts.
BB (Beta genes) have no heat cycle and have their second reproductive systems non-existent, being purely male/female. Some are sterile. About half of the BBs are scentless, where the other half has a very faint and barely noticeable scent. However they have superbly highly developed vomeronasal organs, which grants them an uniquely advanced sense of smell regarding other’s scents.
There was a huge social pressure that these genotypes were to be avoided mating and birthing because of this characteristic. Though with the new ways of thinking of the minds of the youth generation, they are now, slowly but surely, considered valuable and highly sought after thanks to that same characteristic.
A female BB has a normal menstrual cycle and menopause. Male BBs have normally functioning reproductive system.