Overthinking / Negative thoughts

Hi ladies, I am in my last trimester and since I got pregnant , I can’t help it but to over worry for the little 1 even till now that I am about to give birth.. my husband is saying I think too much but is it common to worry or have images about how your baby will become… but whenever I think of it, I start to think of negative things whenever I encounter some special children as a preschool teacher myself .. I want a healthy and happy baby too but many times the fear and worrying keep coming to my mind frequently…