Hey wubanana1245,
From what I can see here, this particular account has not received an heirloom. Single items tend not to just disappear in situations like this, and it looks like there's quite a bit of other content here both from your recent play sessions and previously.
Is there possibly another account or email you may have used in the past? It doesn't look like this one had any heirlooms, nor am I seeing any of the usual signs that content was lost or removed here. I'd try logging in with any other emails that may have been used to double-check whether you may have that heirloom elsewhere. If there are any you can't recall or can no longer access it may help to contact support directly so they can try to help verify and update any other accounts.