Well they allow rape and domestic abuse regularly. Pregnancy is nothing compared to that. Also Humsha is a villain and this would be pretty much in character for her.
Maybe, but I think there is a limit to what can be shown in Pakistan. I mean I have seen pregnancy happening because of rape in drama, but will willingly? Never. I am pretty sure it will be a huge issue in Pakistan if they air it. I remember Mere paas tum ho had issue with censorship as well, even though it did get resolved in the end

but I feel they will be together towards the end of the show...beech mein ammar humsha rahegi