I doubt that'd be possible cus how tf would u put ur own dick inside urself and also there's the concept of knotting that only alphas can do to reach the womb as deep as possible as well as block the entrance so??
if you able to get ur sperm to your own wmb i doubt it'll form any blob of fetus, and as far i got, most omegaverse, the male omega doesn't have like a fertile sperm
of course it's all depends on author, as an author myself i made my own guide book universe for my own omegaverse
in a lot of omegaverse they do have fertile sperm, just less so than alphas or betas. but ive read plenty where some couples are omega man x omega or beta woman couples, esp if the world maintains heteronormativity despite the second genders.
Can male omegas get themselves pregnant? Cause most of the time I see that the omegys have balls and shoot semen which makes me think that they potentially could get themselves pregnant. Unless it's widely known that only Alphas can impregnate the Omegaverse. But that also wouldn't make sense since most of the time betas can reproduce with other betas. So couldn't omegas reproduce with themselves by that logic???