I guess your gynac will ask you to Go by your scan date in this case.

Do you remember your tentative lmp atleast???<br> Your gynac might have asked you and you might be through your initial scans which reflect your scan edd. Your gynac can calculate it for you.

<b><span style="color:#3B5998;"><a href="http://app.babychakra.com/article/2850">EDD Calculator: For An Organized Pregnancy Care</a></span></b>