That isn't usually the case. The free PDF is a subscriber perk, so if you subscribed you should have access to the PDF. If you just bought a copy from Paizo as a one off you wouldn't receive the PDF.
Having said that, since it's still possible to subscribe to the AP starting with issue 1, Paizo can probably switch your copy to a subscription copy if you add the subscription quickly (i'd put it in your sidecart and not complete the order, then have Customer Service complete it for you and mark your original copy as a subscription copy).
You only get the PDF if you subscribe.
Hello Felzeel,
The other posters are correct. The free PDFs are only associated with items that are ordered through the subscription service. I see you do have a subscription to the Adventure Path and that your pre ordered Adventure Path 1 shipped out to you some time ago. So I have attached your subscription to that pre order and you should be able to see the PDF on your My Downloads page now.