Mampam, are you feeling any better?
Inshock, oooh sounds promising hun!! FX for you!!! 
Stubborn, LOL you sound like me. I did a PG test aswell yesterday because I've had horrendous headaches and nausea this week and I'm only CD10. But BFN for me aswell. I swear our bodies only do this when we're TTC!
Tranquility, are you nearing OV time? Can't remember when you normally OV, but it can cause slight spotting. Either that or maybe too much DTD? If you look up mid-cycle bleeding it will say that after AF, you can bleed around OV time or at around 10DPO during implantation... So looking at the fact that you're only CD11, I would think you were OVing... have you done an OV test?
Spinning, if you know exactly when you OVd, then unfortunately I would say that 4/5 DPO is definitely too soon to get any symptoms as implantation doesn't take place until 6-10DPO.
Actually, I was thinking about this... If for some reason the egg doesn't implant until day 10, is that why some people would get a BFP later than others? Because if someone implants on day 6 and another on day 10, that's 4 days head start that the hormones have got to get into the urine, compared to the one who implanted later???
It makes sense in my head... I think... LOL
Big waves to everyone!! 