Ay, first time mom ka talaga, kaya nervous ka! Please have your OB explain your cervical length result in detail, they know your full situation and can tell you exactly what it means for your pregnancy, kaya don't worry based lang sa numbers. A few of us moms in my circle had different readings throughout pregnancy, at ang bawat case talaga ay different. Your doctor will monitor mo closely if needed and guide you what to do next. Trust your OB, yan ang best person to answer this for you! Sending you calm thoughts, mama!