Has there ever been a pregnancy in a soap opera where the paternity of the child was not in doubt?

While visiting my sister this week I was exposed to several episodes of daily soap operas. This was my first experience with this type of entertainment and likely my last.

That being said, as she explained the complex plots I finally asked her if there was ever a pregnancy in the history of soap operas where the paternity was never in question and she could not think of any.

Is this the case? If it is why is that so and what would happen if a soap opera was made that could not rely on this plot twist?