There are many takes on the concept of the omegaverse in writing and many variations to what it entails. This is simply mine. I couldn’t find a not-awkward way to include all this into the story, so here it is fleshed out.
To begin, I don’t use any of the wolf/werewolf/shapeshifter aspects of other omegaverse variants you may be familiar with. There is some imagery of growling or bearing teeth as a sign of aggression, dominance, or warning. I’m not using this to write intense sexual content, male-pregnancy, or dubiously-consensual sexual relations. (However, some of these themes may come up in the story for plot reasons.) My primary take on this universe is on gender dynamics and social situations in different tribes/packs and how they can be challenged or aligned.
Everyone is born with a primary sex: male or female. Their secondary gender does not stop women from looking like women and men from looking like men (in terms of hair patterns, body fat patterns, bone structure, etc.). They are also born with a secondary gender/sex: alpha, beta, or omega. These secondary genders do not present, or develop and become apparent, until the onset of puberty and essentially replace the primary gender for sexual function. Everyone gives off unique pheromones that identify them as their secondary gender.
In regards to Alphas: Alphas impregnate. An alpha tends to be larger, dominant, and more assertive. This tends to go along with aggression and potentially violence, however nothing stops them from learning to be nurturing or gentle. Alphas tend to make good warriors as they can be faster and stronger than their beta/omega counterparts.
In regards to Omegas: Omegas become impregnated. An omega tends to be smaller, shorter, and more apt to comply or submit. This does not mean omegas are physically incompetent if properly trained they can stand a chance against their beta and sometimes even alpha counterparts (this however would require significant, intensive training). About once a month, in a healthy omega, they will go into heat. A heat is a period of time, usually around one to three days, when an omega is fertile and the hormones released during that time cause them to be not only physically hot but also have an urgent desire to have sex. It can impair their judgment, physical capabilities, and desires because their primary drive during that time is to mate. Heats are the only time an omega is fertile.
In regards to Betas: Betas default to their primary gender. Meaning men have penises and impregnate women, and women have vaginas and can be impregnated. Women still have normal hormonal cycles with times of fertility and menstruation. There is no special presentation that identifies them as beta, but rather the lack of any other presentation. Secondary genders present in the teen years (thirteen to nineteen). So if someone reaches adulthood, around the age of twenty, without presenting as alpha or omega, they are a beta. Betas can engage in sex with an alpha or an omega, but they do not meet the physical requirements to completely satisfy or impregnate. Betas are still fertile and can have children, just exclusively within their own secondary gender.
In regards to mating: Mating is simply the term used for both sex and the concept of a marriage equivalent. Scents change during mating, so a mated omega has a different scent than an unmated omega. A mate, or spouse, is marked using the bonding gland. This is a slightly raised area on the side of the neck that contains a gland which is bitten to bond the couple together. According to common knowledge, the bonding gland can only be bitten once and a bond cannot be severed except for death of a mate. There is some talk of being able to break the bond, but it is dangerous. The bond that forms is a physical connection that links the two together. It allows the other to feel emotions and impressions from their partner. No words can be exchanged and it can’t really be controlled (though you can learn to focus on it better and feel it stronger). For example: If one mate was extremely scared, the other would be able to feel the impression that their mate is scared.
You may notice in the story there is no legal age of consent in regards to mating as omegas get mated as young as they present. In case this isn’t clear, this is a fictional story in a fantasy world and I do not condone child marriage.
In regards to birth: There is the tendency for betas to produce betas, and alpha-omega pairings to produce alphas and omegas. This doesn’t mean betas can’t have alpha or omega offspring, it’s just not as commonplace. The same is true with alpha-omega pairings producing a beta. During childbirth, whichever parent gave birth to the now pregnant person would be the one accompanying them to the healer tent where they would give birth themselves. There is also often a doctor (witch doctor/shaman) present especially in cases of concern.
In regards to social dynamics: The short answer: it depends on the tribe/pack. For the most part, people aren’t concerned about primary genders. No one cares if their leader is a male or female, there is no concept of homosexuality or bisexuality because sexual partners are primarily determined by their secondary genders. So an alpha female being mated to an omega female is not something anyone thinks twice about, it is perfectly normal. However an alpha female being with another alpha (male or female) would be unthinkable due to the physical incompatibility. Alphas or omegas being with betas is highly stigmatized and unaccepted because of this incompatibility, the removal of potential fertile mating partners, and the socially important continuation of one’s lineage. Alphas and omegas are also not as common as betas, and a beta removing them from the mating pool is considered wrong. The exact breakdown of what percent of the population is which secondary gender is skewed in the story for several reasons. Different packs/tribes have different situations that have affected this breakdown. So as much as it would be nice to say it’s X:Y:Z percent of beta, alpha, and omega respectively, it’s not that simple.