Help please

Hi ladies. So I was just wondering about implantation bleeding. How long is it suppose to last? Is it suppose to be really light or can it be heavy? I was sure I was pregnant. But then when I wiped yesterday there was a tiny bit of red and then nothing for the rest of today. However this morning there is a whole lot more. I'm just confused. It would be about 3 days before my expected period. I'm not normally early. I'm normally on time or late. Thanks for any advice or opinion.

I did do a pregnancy test. And I had a blue dye... There was a two pack. Both were positive. And the line was getting darker. I was waiting to try with a pink dye when it got closer to my missed period. But then this happened. I am also a high risk pregnancy. I have higher chances of miscarriage as well as premature births. So I'm really concerned. I'm sorry. There is also no clots and a very dark red. I've also been blessed with having easy periods but I'm not having a very easy time right now. I'm having bad headaches and back aches.