The chances of having a normal birth can vary depending on various factors, including your age and cervical length. A cervical length of 2 cm is considered to be on the shorter side, which may increase the risk of preterm labor. However, it's important to note that each pregnancy is unique, and many women with a short cervix still go on to have full-term pregnancies. It would be best to consult with your healthcare provider for a more accurate assessment of your individual situation. They may recommend additional monitoring or interventions to ensure the best possible outcome for you and your baby. As for your due date, it is determined based on the first day of your last menstrual period and can be confirmed through ultrasound measurements. Your healthcare provider will be able to provide you with more information about when you can expect your baby's arrival.