Positive OPK, when will I likely ovulate?

Alright, so this is my and my husbands 3rd month of trying to conceive, so this month we decided to use an OPK to help us figure out when I was ovulating, since the past 2 months I have been completely unsure. I always thought that I would ovulate on the 14th or 15th day of my 30 day cycle, but I was never positive, so I took an OPK today (first response brand) and got an immediate dark test line, and the control line was very light pink, so I am for sure that it is positive. So does this mean that I am ovulating right now, or does it take a few days? Also, my husband and I have had sex a lot this past week, on the 15th, 16th, 17th, 18th, and 19th, so is there any hope that any of that sperm will be left during ovulation? Of course, my husband and I are going to have sex right away when he gets home today, and tomorrow, and probably on Sunday to cover our bases even more, but I just want to make sure that there is a lot of sperm available, so that I have a better chance of conceiving. What do you think ladies? And do you think that I would be ovulating right now, or not for a few days?