Ugh. Help

A clinic told me I was 6 weeks and 1 day, but the ER told me I was 6 weeks and 2 days... they’re putting conception at the 12th or 13th of March... I had sex on the 10th, and sex with someone else on the 15th.... the person on the 10th came inside me and the person on the 15th had erectile dysfunction the entire night and I like was only inside for like a minute at max but did not finish...... if conception was 12th or 13th it would be more than likely be the guy on the 10th right??