Any female ever felt a feeling in their upper abdoman that feels just like a baby moving....?

but they are not pregnant? I am 49 going through Perimenopause. My husband had a vasectomy many years ago and I'm not having an affair. Over the past 2-3 weeks I have had a fluttering, and muscle movement in my abdomen that feels exactly the same as a baby at about 6 months. It comes and goes and is right below the center of my rib cage. It's not gas and it doesn't change where it is. Could it have to do with my uterus or possibly the artery that passes that through that area? I have gained weight despite trying to lose it over the past 4 months.