Am I Pregnant? Period Delay & Possible Conception - Advice Needed

Question
i would like some advice .
i am 24 year old .
i had my last period on the 21 of aug  , i had unportectod sex on the 3rd and on the 4th of sept .
i would like to know if i could be pregnant?
i have a daughter at 2 year old and a son at 9 month's.
i would like to have a some help on this please.

Answer
If you normally have a 28 day cycle (from the first day of your period until the first day of your next period) ovulation occurs on cycle day #14. If your last period strted on August 21, you would have ovulated on September 3 and could only have conceived if you had sex on September 2,3,4, or 5. If you did conceive on one of those days, a pregnancy test will not show a positive result until 14-21 days later. The best time to take a pregnancy test is seven days after missing your next period. If you do not get your period by September 17, wait an additional week and take a pregnancy test.