BBT: could be pregnant?

deep

Hi ladies,

Im 13 dpo today. My temp has been staying up. I tested today with cheap pregnancy strips got BFN.

I have been having flashing smiley since cd14 , today is cd30 still flashing smiley on clear blue digital. I haven’t had flashing smiley that long before.

Could i be pregnant?

How many dpo will i get positive if pregnant?

I have 1 day dip in temp at 9dpo, does it mean anything.

Should i test with first response, is it sensitive enough?