Pregnancy Timeline & Dating: Understanding Your Due Date

Question
Hello,
 I recently found out i.was pregnant by a home pregnancy  test., on January 23rd.
I had gone to.ER.on january  29  . And had a.transvaginal ultra sound  and
Blood test , the.doctor said you'r baby is 5 weeks 6.days and i had.asked does that mean i need to.deduct.2.weeks, and.she said no ypur baby is 5 weeks 6 days ... So i counted back to dec.19th ... I was with my ex.all.Dec, and had.sex with one other person on jan 1st... I dont know when my
LMP was. So o just need a good solid answer im hoping its my bfs

Answer
From the information you provided, you most likely conceived on Jan 2, making the second man the father.  5weeks, 6days pregnant means that to find the conception date you would have conceived 3 weeks and 6days ago, which would be Jan. 2.   Without more information, that's the most accurate answer I can provide.