is this normal?

Jodee

is this dip normal for 6dpo? back story.. I have been working with a RE. this month is the first time I have confirmed ovulation. no meds, just due to changes I have made and getting my uterus baby ready as my RE called it. so today I'm 6dpo and I got this big dip in temp. not sure if its normal. I have also had a headache the past 5 days which is also unlike me. any ideas? my cm is watery/sticky. my cervical position is med/soft/closed.