Conception confusion

Brandie • Mom of 2 girls💕 1 angel in heaven😇 preggers after trying for over 2 years 🧚🏻‍♀️ Expecting twin boys in October/November💙💙

My phone dates my pregnancy four weeks ago but four weeks ago I was on my period obviously.

So I have short cycles like around 22-24 days.

I potentially had sex on the 5th or 6th (feb) when my period ended and I def had sex on the 13th ( feb). I’m just curious as to when I conceived.

Trying for three years prior to this.