If i'm 2-3 weeks pregnant could i have conceived my pregnancy on the 23-25th of august ?

Don't think so...: No woman knows if she is 2-3 weeks pregnant or not. At 2-3 weeks gestation (2-3 weeks pregnant), anything can happen. It is still too early, because conception just happened sometime in the past 1-7 days or so. So, one can do a urine pregnancy test in 10-14 days... If it is positive at that time, then one can say she is officially pregnant.