When should you take a pregnancy test ?

So I am 6 days late and I took two early pregnancy tests when I was 3 days late and another one at 4 days late and both said negative but still no period and I’m on day 6 could it be wrong ? Even though it says I can test 6 days before period ?

I’m so stressed because I’ve always been other before giving birth but after I had him I got my first period February 13 then March 15 and I bled randomly April 2& 4 and got my last period April 14 now May nothing 🥴

I’m formula feeding so I don’t think it’s that but my dr said it could take a while even for formula moms to get back track or maybe I’m just stuck always having irregular periods

Has anyone gone through this ? Or am I being paranoid lol