It may be, and it may not be. You can go to ovusoft.com and look at some charts with implantation dips and compare, but keep in mind, that a dip in the chart doesn't always mean implantation. I hope it is though:) When are you expecting AF?
11-13-2006..If I charted right I ovulated around 10-27...This is the first dip....and the temps stayed high until today....dropped back down to my coverline.....
Best thing to do is just keep taking temps and if it's up after 18 DPO, then test (if you can wait that long). Keep us posted!