I am 18 and will be 19 tomorrow and I am due June 28 2013. It says my ovulation date was around October 5 and I had sex the third and fifth of that month can you tell me which day I conceived

No. It's completely impossible as these times are not exact. They are best guesses by the doctors and not down to the exact day.

Seriously??

Conception dates are give or take a week ( either way) or even up to two weeks.

So you can't know for sure what week it was ( unless that was the only two days you had sex)

So no, there is no way at all to tell which day it was.