Lynn, (LOVE your name btw)
If your test line is as dark or darker than your control, but only on one side that is considered a positive. It is tricky and I hate it when they do that. I only pee on another one if that's my result. I hate trying to decipher those stupid lines.
It's actually best to DTD every other day before you get the positive OPK and then everyday (from the 1st positive OPK) until you are definite that you O'ed. That is, of course, only if you do not male factor issues. Your timing looks great! You should have hit it. If you chart your temps, you can be 99.9% positive that you O'ed once you have a thermal shift that lasts 3 days.
I also O'ed on September 3rd. If you're only using OPK's, then I would start counting dpo two days after your positive OPK. By that method, you're assuming you will ovulate the next day. In your case, your first dpo was Sunday. You're only 10dpo right now so it's a bit early to be testing. Good luck to you and I hope you see a nice BFP in the next few days.