Get your Health question answered in 3 easy steps
A Doctor will be with you shortly
Ask a Doctor Now
147 Doctors are Online

Calculating conceiving date - Online Doctor Chats

Date : 21-Feb-2012
User rating for this question
Very Good Posted in: Getting Pregnant
Answered by

General & Family Physician
Practicing since : 2004
Answered : 40 Questions
User :   My ultrasound measured baby at 9 weeks. Does this mean based on LMP or when I concieved? If the weeks are based on LMP then it would mean i'm 7 weeks right? If not, then does it mean I concieved 9 weeks ago?
Doctor :   Hi
Doctor :   Let me read your query
Doctor :   I am Dr. here
Doctor :   May I know your last menstrual period?
User :   A normal period was 3/13/10. Then I had some light bleeding on 3/29/10
Doctor :   When was the ultrasound scan done?
User :   June 2
Doctor :   Ok
Doctor :   On 29th, was it just spotting?
User :   I just want to know if the baby measures at 9 weeks does that mean when the baby started growing
Doctor :   Ultrasound shall detect it based on the size
Doctor :   and cannot be considered as very accurate
Doctor :   clinical history of LMP is very much significant
Doctor :   usually 2 weeks of variation shall be there b/w the 2 values
User :   Well could I have started bleeding again due to stopping my birth control
Doctor :   and the same is in yours
Doctor :   Ok
Doctor :   So, now for practical purposes you should go by your LMP
User :   Because the 3/13 period was normal then I was taking birth control for 1 week then i started spotting 3/29
Doctor :   Ok
Doctor :   That has to be considered as LMP
Doctor :   meaning the 29th
User :   would going by 3/13period sound practicalfor me being 9 weeks or the 3/29
Doctor :   So you were scanned on 65th day from your LMP
Doctor :   meaning 9 weeks after 3/29
User :   Yes but I thought it takes 2 weeks for the baby to implant and stuff
Doctor :   Right it does take
Doctor :   ultrasound goes by the weight of the fetus
User :   So if the 3/29 would be LMP then when did I concieve
Doctor :   2 weeks from then
Doctor :   usually
Doctor :   again if it was after the frank cycle, then your ultrasound does sound more accurate
Doctor :   considering 3/13 as LMP
User :   What is Frank cycle
Doctor :   that means conceived around 3/29
Doctor :   frank cycle is the normal period
Doctor :   like on 29th you did mention it was just little blood loss
User :   So then that would mean since the u/s says I'm 9 weeks then i would count 9 weeks back to find out when I concieved
Question is related to
Lab Tests
© Ebix, Inc. All Rights Reserved.
All the information, content and live chat provided on the site is intended to be for informational purposes only, and not a substitute for professional or medical advice. You should always speak with your doctor before you follow anything that you read on this website. Any health question asked on this site will be visible to the people who browse this site. Hence, the user assumes the responsibility not to divulge any personally identifiable information in the question. Use of this site is subject to our Terms & Conditions
Already Rated.
Your rating:

Ask a Doctor