I still haven't received a single godd*mn heirloom shard why!!!?

Well if you're not 100% certain, which is very hard to be when determining how many packs you've opened, then the likely answer is that you haven't yet. It feels like a lifelong grind trying to farm the Apex Packs, but 500 is a massive load when you consider the effort needed just to get one. I don't know if the looting algorithm is the same for each platform but on Xbox, I believe one pack is reward for each level from 1-10, and then every five levels up to 500. So, when doing the math there, that would only be about 110 Apex Packs getting to max level. And you only get a handful of packs from the premium battle pass, including the grand total of the Apex Coins that it provides. So basically, if you want to get your heirloom within the next decade, you'd have to buy a ton of them because the random drop chance is so unbelievably low, if there even is an actual drop chance. For all we know, the heirloom loot table could have programmed to always drop on the 500th Apex Pack. Happy hunting, I think.

PS: I would advise against clicking on random links such as the one the user above me posted. Call me cynical, but you have to remember: electricity I get. People? I don't. That's how I got here.