Cervical Muccus Before Period Pregnancy And Ferning?

Pregnancy and Ferning? - cervical muccus before period

I am almost 23 weeks pregnant and went to the hospital for pain in the right upper abdomen. The doctor said everything was fine and told me I had a lot muccus cervix. A sample of it and saw a film and says what he saw was ferning. Is there something I need to worry? The dr. wants me to continue with my physician. But it is an indication of ferning something?