positive pregnancy tests? confused.

okay so i got a positive on a pregnancy test last wednesday. took another one the next day. it was positive. so i put it into glow to calculate my due date...and it said i was only 2 weeks and 6 days pregnant at that time because of my LMP. i’m just confused because everything i’ve read said you shouldn’t get a positive pregnancy test that early? because at 2 weeks you’re not technically really pregnant yet. i’m 3 weeks and 5 days today and everything i’m reading says i should’ve just got a postive recently or should be getting one soon. i don’t know how i would be further along than that because i didn’t have sex at all with my fiancé during my period week or before. and according to me being pregnant i got pregnant literally almost exactly after my period ended. fiancé and i had sex the day after and all week the week after my period which wasn’t my fertile week. could i have ovulated during that time and am further along than what i think i am?