Hey OGShwager,
Not quite! To clarify, you have a 0.045% chance of getting Heirloom Shards when opening an Apex Pack, as detailed in our FAQ and the article here:
Apex Legends™: Minimum Global Drop Rates
If you've not gotten shards after opening 500 packs, you'll be guaranteed to get them on the next pack. You otherwise have that same chance of getting them whether on pack 1/500, 10/500, 250/500, 500/500, and so on. It'll be the same odds until you reach the point where it's guaranteed, if you haven't received them by that point.
Keep in mind as well that these Pack Types do not count towards the Bonus Heirloom Shards:
- Collection Event Pack
- Thematic Event Pack
- Milestone Event Pack
- Collection Retro Pack
- Any packs that might provide replacement items