At 3 weeks and 5 days pregnant, it may be too early to detect a heartbeat or see much on an ultrasound. However, you can still schedule an appointment with your doctor to confirm your pregnancy and discuss any concerns or questions you may have. They will be able to provide guidance on when the best time for an ultrasound would be based on your individual circumstances. Generally, most doctors recommend waiting until around 6-8 weeks of pregnancy for the first ultrasound, as this is when the fetal heartbeat becomes more visible. However, every pregnancy is different, so it's important to consult with your healthcare provider for personalized advice.