late implantation?

I thought for sure I wasn’t pregnant because I had been testing almost every day since 9dpo all the way up to about 16dpo and had nothing but negatives. 16dpo was my day after my period was supposed to start, negative. 3 days later my period still isn’t here so I get a digital test almost certain it would be negative but low and behold it says pregnant. 19dpo at that point. Did I implant late? Or did the tests I was using just not pick it up? I was using easy@home. I thought you would have to be further along to get a positive digital.

16 dpo

19 dpo