I think Sami will eventually come to EJ to tell him that the baby she has (Grace) is their child together. I think Nicole, being the witch that her charecter is, and knowing FULL well that isnt EJs baby, will convince EJ that he needs to do a paternity test on the child since they dont really know what Sami has been up to since she went to W.P.
Obvi. when the test comes back that EJ is not the father, Sami will be flabbergasted, as she knows she hasnt been with anyone else since that day.
That will get the wheels in her head turning, She will go to Dr. Baker for some sort of answer, and he will point her in the direction of Nicole, since he is no longer recieving money from her, he will have no problem throwing her under the bus.
Just my 2cents
