No Visitation b/w My Child & Inlaws ?

Am I wrong for not wanting my Inlaws (particularly mother in law) to see / spend time with my unborn child when he arrives. Okay so before finding out I was pregnant we were all fine, my Inlaws loved me & I love them. A few weeks after reveling to her (my mother inlaw) I was pregnant it was like a switch had flipped. She would act real snotty when I came around, she would give me these half assed hellos & catch a real stank attitude when I went over to see them .. I realized I was done with her a few weeks ago, I had just gotten out of my ultrasound appointment & went to go show her photos of her grandson. she acted like a straight bitch (excuse my language) she had a stank face, stank attitude & didn't not even crack a smile. I was furious, just because she was mad at her son did not mean to take it out on mine ! I haven't spoken to her since that day and honestly do not plan on it. I am now having doubts on allowing my son to visit or spend time with her only because i feel as if she is mad at me or gets angry at her son (my SO) she will take it out on my son. I would rather allow for them to bond & visit from a distance than for her to act "sometimey" with him. Am I Wrong ?