Same here! I charted last time I got a BFP and no dip!
Not always. In fact, the only way to tell if a "dip" could be implant related is in hindsight. Temps can spike and dip for various reasons throughout your cycle. Lots of women see a dip around 7-10dpo and are hopefull until af shows up.
My last bfp never had any kind of dip. I stared hard at it looking for a sign, lol. No dip and a definite bfp. Good luck!