I know how you feel
My husband and I went through the same thing for well over a year before getting pregnant. I tried everything---Ovualtion Predictor kits, I read books, I did research on the internet, I told my husband not to take really hot showers--which is not good for sperm count, told him to wear boxers and not tighty whiteys
All of the above advice is good and it's up to you what method you would like to try. The method Isabel Kitty mentioned my husband and I tried but with our schedules and his high pressure/long hours career it just wasn't possible to have intercourse every other day.
If you typically have a 28 day cycle you normally would ovulate at around day 14, or a 30 day cycle around day 16. The BEST way to tell when you are ovulating or just about to ovulate is to check (kind of gross) your vaginal discharge....When it becomes clear and sticky (like egg whites)you will be ovulating I think within the next 24 hrs.
The method that worked for my husband and myself was to have intercourse 2 days before, the day of, and 2 days after ovulation.
Relax, don't put pressure on each other.........even go for a romantic weekend getaway around the time of your ovulation and you just never know............
Good luck and if you have any other questions or just need some
support from someone who's been in your shoes just send me a private message.