so i had sex for the first time aug 4th and then i got my period the next day , i had sex again on aug 17th, 18th, and 23rd.. i got a positive on the 5th of sep. but my sister is telling me thats way to soon for a postive to show up.s o im wondering when did i conceive at the beginng around my period or towards the end of aug around the 17th or 18th and i have a normal cycle... please help thanks in advance

Going by the dates, it wouldnt be too early to get a positive.

You probably got the timing right around the 17th/18th. When you tested it would have been two and a half weeks later (the time between ovulation and your period is around two weeks)

It's very possible that the 17th is about the time you ovulated, and definitely enought time between then and the 5th to get a positive test.

Congratulations on your BFP

Any of those 3 dates that you could have conceived around would give you an accurate result now so your sissy is wrong

Congrats x

Congrats Hun