Your last menstrual cycle (LMP) is never accurate that's why ultrasound is needed to determine the age of your fetus so follow that. 5 weeks is way too early to see anything so worry not and wait for your next appointment. Although some can already see, majority cannot. Normally by 8 weeks and above you can see your fetus already.
dont panick and worry too much. 5 weeks are too early and also LMP is not always accurate! wait a week or 2 , im sure you'll see yr baby