Implantation bleeding?

Hey guys I'm on cycle day 24, 5 dpo! Today I have been feeling very fatigue and nauseous on and off throughout the day. I have also had really sore boobs and I just went to the toilet and when I wiped I had some blood the size of a pinky finger nail... I have had a tiny bit of cramping and this morning I went to order some food and felt really hot and sick... With all of these symptoms do you reckon I've just had implantation bleeding? It's literally like having a paper cut and a little bit of blood comes out that's how I can explain how little there was but I've never felt like this in a cycle before and I've been TTC for 16 months! My AF is due next Friday 19th December.... Help? X