First of all, don't panic. Has it been a few days since it was shipped? It may take tracking numbers a few days in the shipping courier system to reflect an update.
If it has been a few days, this is still normal and can happen if you select Standard Shipping on your order. To check if you selected standard shipping, go to My Orders, then click on the order number.
Then scroll down until you see “Shipping Method.” Standard Courier means your order shipped via Standard Shipping.
In this screen, you can copy and paste the tracking number into the shipping carrier's website. If you get the message below:
It means that your order has bulk shipped from our facility in Shanghai. Once it reaches the destination country and is sorted, the tracking number will update. It may take several days for the tracking number to update after it is created.
If it has been more than a week after your order status was 'Shipped' and tracking number still isn't working, then please email firstname.lastname@example.org for help.