Is it possible for a BFP 4/5 days after sex

[Simmy85]

Hi all, I feel like this is highly unlikely but just a question.
If you had sex on the 10th of December (Sunday)... late at night (near midnight)
Would it be possible to get a BFP on the Thursday the 14th of December at all???
I'm probably further along than I expected...
Like I said it's highly or physically impossible lol but I just wondered...

Also I'm a 26-28 day cycle usually
LMP: 20 November
Estimate ATM 6 weeks ish
With a very long OPK it seemed like it was positive on the 2nd of December and even on the 7th of December.

[samrae]

I would say its not possible, but if you got a BFP, then its probably from ovulating before you LMP on Nov 20. Are you pregnant?! Hoping so!