BBT chart help

this is my first cycle temping so I don't really know what to expect, but this is my chart so far:

I'm trying to figure out if the big dip today is AF on her way... I think I'm actually 8 or 9 dpo (based on o pains) or could this be an implantation dip? I started having an odd heavy and sore feeling my my uterus this afternoon. This is not a normal AF pain for me. Also, my cervix is SUPER high... I can't reach it at all. Any thoughts are appreciated. Thanks!!