around march 21 but no one can be 100% certain
Somewhere between 3rd and 9th December 2005.
Subtract fourteen weeks (7 days x 14) from the date of the ultrasound.
May
32 days previously
31st March or thereabouts
Around Jan1st
99% probability it was between 10 weeks & 10 weeks and 4 days ago.
just 11wks and 6 days before october18
Erm ... 20 weeks and four days ago ... Dohh!! Look at a calendar and count backwards 20 weeks, then backwards 4 days - there is your estimated date of conception.
16 weeks and 5 days ago!!!
Believe the sonogram.
you conceived somewhere between may 13th to may 18th or about 14 days after your LMP The 7 weeks 3 days is nominally from your LMP if you have a 28 day cycle. See the Related Links for "Pregnancy date calculator" to the bottom for the answer.