Help me relax!

So I read that some women's babies stop growing after 8 weeks but they don't find out until their next appt at around 13 weeks. Wouldn't the body want to rid of something that is not alive? It makes me so anxious because I'm currently 11 weeks, haven't seen my doctor since 6 weeks, and will not see him until 13 weeks. 😔 How do I know everything is ok?!