To be honest, unless you have a "full flow" between now and Saturday, you are best waiting until test day. You really can't tell much from anything odd happening at this stage. Early testing will almost always be false. But I know that the 2ww is extremely frustrating.
It may be ok, providing you're not bleeding properly. Looking at your dates again, I'd say you could test accurately 1/9 as that's 16 days after EC. A lady on another thread got a BFN on day 14, but a BFP on day 16 I think. If you bleed properly, then it's almost definitely negative. I know how you're feeling believe me!
Well we got a BFN on our 4th cycle testing on the day that the hospital said. Thought nothing of it until I realised a week or so later that AF hadn't arrived. Retested to discover that I was in fact pg. Ds2 born the appropriate time later.