I am really very confused. Shaila claims Saahil is the father of Mohini's child. But they have not shown Mohini & Saahil talking exactly about her pregnancy or child yet.They were only talking about a secret between them. Even also when Ganga visited hospital chasing them,she was not shown to overhear their conversation with the Doctor.Only the Doctor told Ganga that Saahil is Mohini's fiance.
Also when Ganga visited Shaila's house to grill her, some1 was giving Shaila blank calls. When Ganga questioned Saahil about his dancing with Mohini on RAM-NAVAMI, he could have given an explanation.But he boldly set her aside.If he is responsible for Mohini's pregnancy,he could have behaved like a thief caught red-handed when Ganga saw them talking on the terrace in the mid-night. Also there he could have given an explanation but he left the place as if he has nothing to do there.
I think someone is behind all this confusion. Someone may be trying to separate Ganga & Saahil by creating misunderstanding between them with the support of Shaila and the Doctor by using Mohini's pregnancy. I think it is TRIPTI( Mishti of KAISA YE PYAR HAI) as she is shown to have a great concern for Saahil. I AM JUST GUESSING!!!!