I had sex on the 29th of September with guy A I'm unsure if it were inplantation bleeding or a period which was on the 7th of Oct After my period or inplantation I had sex with guy B multiple time My due date is July 15. Have they given me this due date because I told them my period was on the 7th so they go by that? Or does the sonogropher simply go by the measurements of the baby? My earliest scan was 9w 5d