Clearblue digital saying not pregnant

So I just found out I’m pregnant , I found out at 12dpo and currently 14dpo , my first response are slowly getting darker and my regular clearblue is finally showing a line which is a good sign but I’m just afraid my hcg levels arnt rising , why isn’t the clearblue digital showing pregnant yet? The first response early response digital showed yes , now I’m just getting concerned , also idk if this helps but I think I had implantation late around 9 or 10dpo