Yes, errors in ultrasound can occur, especially in the early stages of pregnancy. By the 20th week, the sex of the baby can usually be determined with higher accuracy, but there is still a small risk of error. If you have doubts or questions, it is better to discuss this with your doctor or have another ultrasound to clarify the sex of the baby.
At 14 weeks, it's very early to determine the baby's sex, which is why ultrasound technicians often make mistakes. If the ultrasound technician is very experienced and the ultrasound machine is not old, then it's unlikely to be a mistake. If it's very important to you, consider going to a different clinic to double-check.
At 20 weeks, the answer is more reliable than at 14 weeks. Until 18 weeks, the sexual organs are not yet fully formed, and sonographers only make assumptions based on the shape of the genital tubercle. After 18 weeks, everything will definitely be fully formed and visible.