I have asked this question before .. but my recent scan has threw me again -_- i had an early scan on the 30th of march which put me at 8 weeks gestation with a edd of 7/11/16 i asked people when i would of likely concieved frm sex in 30th of jan or on the 14th febuary ... which did put my mind at ease ... but i had my "12 week" scan yesterday 12 of may which put me as 15 weeks gestation with a edd of 3/11/16 ... from the conception calculaters online it says likely concieved 8th of feb to the 11th of feb which dont make sense as i didnt have sex with anyone in them dates nt even 6 days b4 which they say sperm can live by ... is it possible the baby is just big and the dates were thrown im even more confused now tbh i have my ovulation dates wrote down for febuary which were between the 13th and 16th of feb as a rough estimate frm going period so im.sure i should of had period 1st week of feb to of known that or was it implation bleeding but that would of mean concieved b4 then sorry i know its confusing i just need more advice not a bashing thanks in advance xx