Marginal Cord Insertion

My doctor told me I have this during my 20 week scan and made it sound like it was nothing to worry about. Just told me that it could effect the baby’s growth and to come back in 6 weeks for another ultrasound. My appointment is tomorrow so, of course, I decide to start researching EXACTLY what it means and I am kinda freaking out! I’ve read words like preterm labor, miscarriage, and hemorrhaging, also to schedule a c section. Yes this was from a credible site and not from Wikipedia... just wondering if any other mommas out there have/had this also and what was your experience?! Thank you