Pregnant with Enemy Alpha's Baby EAB

I got drunk during the Annual Alpha Conference and accidentally slept with Anton, the Alpha of the rivaling clan!
I managed to sneak out of the hotel so that I wouldn't embarrass the pack. I told no one other than my younger sister, although I did not mention who he was.
The present: Three weeks later, I reached adulthood and was about to take over as the pack's Alpha. I would be transforming for the first time at eighteen, awakening my inner wolf as everyone watched. I was on my knees, using all my strength to transform… But nothing happened. Had I failed?
Not resigned to my fate, I tried again. But that was when my heart hurt as if someone was grabbing it and my belly heated up as the rest of my body screamed in pain… I drop to the floor, unconscious.
When I woke up, the first words I heard were from the doctor.
"She's pregnant…"
In our world, any werewolf pregnant with children not belonging to their mates were treated as pariahs, oppressed by one and all. I did not dare to look up at my parents, who would obviously be disappointed.
"Baby," said my mother. "Just get an abortion, and we'll continue the ceremony. You are still the Alpha of our pack.
"Ellie," said my father. "If you don't get an abortion, you will never be my daughter ever again.
As much as I loved my family, I was the only one my child could count on. That was why I decided to leave home.
Thankfully, my younger sister managed to get Anton's number, but the only thing he said over the phone was, "It's been so long. I can't remember what really happened."
So, from now on, I would be a single parent to my child! I swore to give him the good life and to help all pariah wolves find a place to settle!
Years passed, and Anton was almost thirty. With his father's insistence, Anton finally found himself a mate… But who could explain why she was so disgusted with him?