NEED ANSWERS

So I was wondering , how come your a month pregnant at 2 weeks like I fixed my calendar to my last period and it jumped me to 4 weeks 5 days but I know for a fact I got pregnant like 2 weeks ago during ovulation .., someone help me out because idk if I’m 2 weeks pregnant or a month pregnant by calendar I just wanna be able to tell people how far along I am ‼️