Hallow Dear, The egg is released 14 days prior to the next expected menses. Egg has a life of 24 hours and sperms are active for 72 hours. Hence, a period of about a week around the day of ovulation is considered as Fertile Period. So, when you count Fertile Period it should be counted in respect to the date of next expected menses. Commonly available tests for pregnancy evidence are Pregnancy test on urine and Beta hCG test on blood. Pregnancy test on urine is reliable usually about a week after the missed period; earlier they may report false negative. Beta hCG test gives reliable report 10 days after the last unprotected sex; i.e. 10 days of conception. In short there is no test which will detect the pregnancy on next day of intercourse or conception. The very fact that your pregnancy estimation has been reported as 6 weeks and 5 days (which make 47 days and not 45 days), it seems that this estimation was calculated by ultrasonography. In very early pregnancy, this calculation has variation of few days. So you cannot take it as exact 47 days. Moreover, though all days apart from fertile period are theoretically safe period, it does not happen so practically. We have seen many cases conceiving few days away from the fertile period. And finally you have not mentioned the days of intercourse in respect to the menstruation. It is very likely that in few days of those 45 days of your coexistence, your husband has impregnated you. I hope this helps you to recalculate your dates. Now believe in your Obstetrician and plan the antenatal care accordingly. Dr. Nishikant Shrotri