Period late, brown blood in morning and then nothing come afternoon following to the next day?

We are currently TTC and my period is 3-4 days late. I thought I had gotten AF yesterday morning because a bit of light pink was there when I wiped so I put in a tampon, a couple hours later I took it out and it was just a brown colour (my periods are always right on time and it’s like a waterfall on the first day). I didn’t wear a tampon for the rest of the day or today and I still haven’t got my period? Could this be late implantation? Or am I still out for this month? Going to test in a couple days of it still hasn’t come.

Also, I had done a digital test day AF was actually due to come and it was a ‘No’. But I’ve had people say that digital requires more hcg than a line test..