Could there still be conception?

So I thought I had missed my ovulation window so I stopped using my ovulation tests. I started having mittelschmerz yesterday morning and it just got worse throughout the day and I didn't think twice about it...so it's about 6pm and its the worst of that day and my husband said to take an ovulation test. So for the heck of it I did and its a smiley face!!!! So we BD a half hour later. I also used PreSeed which I heard can be useful in getting pregnant since it mimics CM. I still had mittelschmerz throughtout the evening but not nearly as bad as it was and this morning I took another ovulation test to see if I still had a LH Surge and it was negative and I feel tender around my abdomen but really nothing that bad...just maybe a twinge? Can conception still have occured if I was a few hours away from ovulation? I know the ovulation test I used (ClearBlue Easy Digital) said that when you have a positive, it means you'll be ovulating in 24-36 hours. I just want to know if we could have concieved or if I was too close to ovulation for anything to occur.