ovulation and conception

so, according to the positive clearblue digi on the 17th, i ovulated around that time. hubby and i bd every day the week before and last time was the 17th. hubby went on a business trip the rest of the week so we def concieved that week.

i ovulated late on cd 19, and according to my lmp i should have been around 7w 5 ds. but according to the last ultrasound im only 6w 5ds. i know sperm can last a few days, but any possibility the dates line up????