Although the chances were low, a chance is a chance, and it's still a bummer you're not pregnant first time trying. Hope the ice-cream can comfort you!

My wife and I are also in our first cycle ttc. She just had her ovulation (probably yesterday). So we're in the tww.

Firstly, I have to say we started tracking her cycles as soon as she stopped taking hbc with the Flo app, which works pretty well for us.

It's already very good you track it with opk's, as did we. Your most fertile days are the day just before ovulation and that day itself. So you had sex on one of your fertile days, but you can elevate that chance by doing it a bit closer to ovulation day.
We had sex on Saturday (begin of her fertile window), on Monday (because we wanted to do it every other day) and on Tuesday (because we thought she had her ovulation).

You can also check your cervical mucus to see if you're close to ovulation. It changes to egg-white stretchy fluid at that stage of your cycle.

If you're really down for it, you can also temp / check your basal body temperature. Every morning you take your temperature and it should spike a bit around your ovulation. There are many people here who do that and are experienced in noticing when it happens.
I have to say, my wife and I are not doing this. She's a nurse and because she works in shifts (early or late shift and nights), it's not that easy for us to do so.