16 weeks always worried about the baby!

Hi everyone I feel so crazy! I am always worried about my baby and this is my second pregnancy which makes it even more odd! I have had some friends that had stillbirths, genetic disorders, random problems.  Although we have no Down syndrome that runs in our family or any genetic disorders I am still SO worried! I don't even know what to do to calm myself! I waited 3m after I stopped taking my bc to try to conceive just to be extra careful and I eat healthy a lot of natural or organic things plus take my vitamins.