I'm so sorry
...all your symptoms and tests seemed so promising last month
Temping has always worked really well for me, as well as opks. You take your temperature at the same time every morning, preferably after 3 or more hours of uninterrupted sleep and before doing anything else (talking, drinking, getting up...) and record your temps on a chart -
Fertility Friend is a great site for charting, and you can also mark any symptoms, opk test results, illness etc that might affect your temp on it, and it predicts your most likely ovulation day. You should see a rise in temperature just after ovulation, and your temperature will remain higher for the rest of the month (or longer if AF doesn't arrive).
Obviously seeing a rise in temp after ovulation doesn't sound particularly useful on the first month, but used in combination with opks it's great, as a positive opk should be followed by a sustained temperature rise if the LH surge resulted in ovulation (it doesn't always). It's also great for predicting when you will ovulate in future cycles once you can match up days of ovulation to changes in cervical mucus etc.
It's best to use a BBT thermometer that gives your temperature to 2 decimal places rather than just one, as changes in temperature can be quite small. I really would recommend it though!
Good luck