flutters in lower abs

I've been having fluttering in my lower stomach. I am a 37 year old woman and I have been tested for pre menupalse which was negitive as well as ultra sounds and cat scans of my liver, stomach, pankris, kidneys, gall bladder-Although, I do have gallstones, I am not pregnaunt (pregnant) because I have not been sexually active for 3 years. I also have not had a period for 4.5 months and also an ultra sound of my reproductive organ, my overiy, utrus, and all was normal. I am consipated though. But I just really want to know to what the painless flutters in my lower stomach are. They bother me all the time for the last month or so. I have 2 kids and it kind of feels like baby kicks, but it cant be a 3year old baby inside me plus I was tested for being pregunant.