HELP!!!

Amy
Help!! So I started getting faint lines on tests the I bleed four days early but it only lasted four days I thought I had a chemical. That was a week ago. Two days ago I took this test as I heard it's possible to get heavy implantation! So this is defo a bfp right? So then I took a test this morning and bfn?!! Any help would be great! I'm going mad over here!!