Implantation bleeding?

Manda • I`m 30 and have 2 beautiful girls
So I posted on here earlier asking for some advice. I was due on the 30th Dec, I am on CD36 which is the latest I have ever been. For the past week I have been getting nauseaus every day, my breasts are huge and are tender and I have been getting cramps and light spotting but no signs of AF. I did a test yesterday and it was a BFN. Today I have been cramping a lot and whenever I wipe there is blood but there is still no signs of AF. Could this be implantation bleeding or is it just my body showing new AF symptoms? Thanks!