Very concerned about conception

Patient: I had my period on August 3 it stopped on August 10. i am now 5months pregnant. when did i concieve?

Doctor: Hello,Thanks for the query.If you have had a regular menstrual cycle and surely remember you last menstrual cycle to be August 3rd, then you are about 24 weeks 4 days of pregnancy. This being calculated from your dates and the probable conception date would be August 17th. But not all menstrual dates are correct and the confirmed gestational age is checked by an ultrasound at 12 weeks and the pregnancy is dated accordingly.There is nothing to be concerned. Follow the date of gestation as assigned by your gynecologist.Hope this helpedRegards