Help

Hey ladies,  I need a little insight.  I ovulated on the 1st of Dec.  Had sex the 27th of Nov and the 1st of Dec.  Last week I started having a weird taste in my mouth, felt nauseous and certain smells make it worse.  Period was due to start the 7th.  I have never been late (unless pregnant). I took hpt but negative. I started having a very light pinky discharge on  the 9th.  Yesterday about mid day it became heavy with clots but no cramps.  Today it is way less bleeding.  Still no cramps... but I feel very dizzy and nauseous.   This would be my 9th pregnancy (5 children) and i never went through implantation bleeding with any of them.  I am 41 and I realize pur bodies change over time.  Could this be implantation and my uteran lining is just heavier than normal?   Should I wait a week to test?  Need advice.  Thank you