No sense of smell

I (31f, non smoker, no health conditions or medications) barely smell anything. I don’t remember a time when it started, so I’m assuming I’ve always had a weak sense of smell. I have two babies, and can’t smell when they pooped. (I can sometimes smell it when I’m changing them). I can’t smell if something is burning on the stovetop, even if I’m standing right there stirring it. I can smell some things close up, like my daughter’s shampoo in her hair. I don’t ever smell something in a large space, such as when coworkers say it smells weird at work. There doesn’t seem to be a pattern to what I can or can’t smell. What could cause this? Do I need to pursue this? The lack of knowing when my baby pooped is frustrating, and the lack of smelling things burning is scary. I’m really just wondering if there could be any concerning cause.