Although my story is irrelevant to what yours will be like, here goes:
TTC 13yrs, lost 3 at 12, 7 then 9 weeks. 2 rounds of failed IVF. No fertility issues found in either DH nor myself. Mid 40's now and have a dog, as the likelihood of ever having a child is almost zero now.
I never had luck with OPK's, despite tests showing I ovulated. I used a reusable OPK called 'maybe baby' that uses saliva to determine fertility. Other brands are available online. In the long run- they were cheaper than 13yrs of single use opks!
Being a healthy BMI really can help, as can reducing stress. Yes, of course you will hear of overweight and obese people getting pregnant, but it can have health complications.
Some partners find TTC stressful too. Some prefer not to know every detail of your cycle and the added pressure of feeling to need to perform during your cycle. If possible, have sex at other times of the month also, book a weekend away when you might be fertile and try to keep it fun. IF you miss the fertile window one month, try not to stress.
At 30, you need to be actively TTC 12mths before your GP will do any initial blood tests.
Not saying all the above is relevant to you OP- just info I've since picked up along the way. Best of luck with your journey x