April period was 15-19 which was short dr says my ultrasound on july 10 dated10.5 weeks had normal period may 11-17. when was conception likely ?

May 13: If you were 10.5 wks on 7/10 then conception took place around 5/13. How that squares with the dates of your period on 5/11-17 i can not say if the 10.5 wk pregnancy was living. Some women will report some bleeding or spotting around the time a pregnancy implants on the uterus but an amount of bleeding comparable to a period would be very unusual.