5 days IB or early AF?

Hello, this is our 2nd TTC cycle after a miscarriage on April 6th. 2nd month I'm using Clomid 3-8 DC and Estradiol 9-14 DC.

My cycles are pretty regular, around 28/29 days. Temps are also regular, no shifting. Only drop on AF day.

This month I O'd on D14/D15 and, on D16, my temp has risen.

We BD'd on DC11, 12, 13 and 16.

So, this cycle:

Dc 24 - Temp has drop from 37.19 to 36.94º and at 6PM, light pink mucus.

Dc 25 (10DPO) - Temp has drop to 36.9º and darker mucus.

Dc 26 (11DPO) - Temp has risen to 37.01º and jelly-like darker mucus.

Dc 27 (12DPO)- Temp has risen to 37.03 e darker mucus.

Dc 28 (today - 13DPO) - temp drop to 36.77 and pink spotting.

I've posted also this month chart so you can check it out.

I don't know if this is important, but on 5dpo, when I got out of the bed, I've felt dizzy and nauseous. Headache since then. And left side pain, even though I think I O'd on the right side.

Also BFN today. But has the drop spike was today, could the Implantion be only today with 4 days of spotting? Or is it early AF (assuming the first day of spotting)?

What do you think?

Thank you!