Pica without iron definitely? / chewing on sponges

Hi guys, I found this subreddit - and generally pica- by accident Sooo… I’ve ve been chewing on sponges since I was I kid, even have fav types and stuff for them (Upholstery foam, LED,EVA cosplay foam and good quality bathing sponges are great!!! I also recommend natural sponges- different but worth a try ) Never carved sand, clay. Sometimes vax and paper but never enjoyed it as much as sponge. Really I cannnot not to eat it when I’m near one

I’ve red pica is caused by iron deficiency, but I’m 100% sure I never had it, cause I’m a blood donor and they check this thing every time !!!

So… could I’d be pica? Are there other causes? Do I have to get professional diagnosis ? Please tell me something uhhh