Implantation bleeding?

Hi all

I was due for my period 2 days ago but it didn’t arrive. I took a pregnancy test yesterday morning - negative result. After that I started spotting very lightly on and off through the day, a very light pink colour and went through a few bursts during the day of needing to pee a lot.

No spotting overnight, but mid morning started very light bleeding again - very dark brown colour today. Not enough to fill a panty liner but a little more consistent today.

I also had sharp pains in my lower abdomen for a couple of minutes last night.

Does this sound like implantation bleeding? If so when would it show up positive on a pregnancy test? Sorry...I’m a newbie to all of this!!