Have we timed it right?

hi ladies , just need a few opinions , me and hubby bd ,23rd 25th 27th 31st aug bc i thought i had ovulated early , any way did a opk on the 1st sept with fmu and it was a blazing positive , so i got my O pains on the thursday morning and bd that night , do u think iv missed it or would the 31st of covered me for the time thanks susan