this makes no sense

I hope someone can help. And the end of December I thought I was experiencing pregnancy symptoms, we did the deed around ovulation. The day I went to take a test my period started ( or so I thought) it was light lasted about three days. Well this beginning of January. So here we are I assumed I wasn't but I can't explain the peeing eating and sore almost unbearable boobs when nursing...I've never experienced implantation but it was 12-13 days after sex isn't that too late?