Mama Natural’s take on tests:

https://www.mamanatural.com/third-trimester-tests/

How to Avoid GBS naturally:

https://wellnessmama.com/8680/avoid-gbs/

Other resources:

https://www.parents.com/pregnancy/week-by-week/16/

https://www.thebump.com/pregnancy-week-by-week/16-weeks-pregnant

https://www.whattoexpect.com/pregnancy/week-by-week/week-16.aspx