I had my dating ultrasound done around 7w 4 days...or so i thought...turns out they told me at the ultrasound that i was actually 8w 4 days...does anyone know how this is possible? Please let me know what you think of my theory: I think it is a boy.. i think we had earlier implantation and i think the sperm swam faster and implanted early bc its a boy and thats where the extra week comes from...just a thought... has anyone had a similar experience and dated further along in their dating ultrasound and then had a girl? comments, thoughts welcome and appreciated! I still have about 8 w to go before i can find out gender...or does anyone have a logical explanation as to why i would be a week ahead than what was previously thought based on lmp?