Similar symptoms??

Hey 
So I am now about 9 dpo, we had sex on the day I ovulated and the next 2 days. 
For the past 4 days I've been so tired, like naps in the afternoon when usually I'm fine, I've been craving fish which I hardly ever eat and vivid dreams almost every night (again not normal for me). I had a bit of spotting today like a rusty brown colour but that's been it. 
Could it be implantation bleeding? Anyone got similar symptoms?