OPKs and the two week wait

So it's month 2 of using OPKs to chart ovulation. Last month, I wasn't sure if I was going to ovulate because my cycle was just going back to normal after the depo. I was expecting that if I did ovulate, it would be on CD14 or 15. I'm not going to lie, I cried on CD14 when the little test line was so light. But to my surprise, on CD15, the test line was definitely darker than the control! It was definitely a positive. Now a month later, I thought I knew what to expect. But, on CD13, the test line was fairly dark- but definitely not as dark as the control. That threw me off a little because last month all the tests up until to CD15 were as light as could be. Then, CD14, the test line was pretty much non-existent. And today, CD15, again the test line was just barely visible. So where was my positive test? Did I catch the beginning or end of it on CD13 and I ovulated earlier than last month? Or did I not ovulate at all?

I've been pondering the 2 week wait as I wait to ovulate. Last month I thought "Now I ovulated! Certainly it will happen this month!" This month I'm thinking that it's so unlikely to get pregnant on the very first try. But now this is our second, surely it will happen this month! At what point does your mindset change? On your 6th cycle trying, do you start to realize "It just might not be this month"? On your 12th cycle do you start to give up? I know, in a way, that there is only a 1 in 5 chance that this will be the month. But at the same time, I know that I will cry the day that AF comes... if she comes this time.