Sorry that I kind of rambled a bit...
I charted cervical mucous and OPKs at fertilityfriend.com. You can use the free version, though I bought the VIP when it was on sale (check facebook). It's going to help you because many women do not have a "regular" 28 day cycle, so you could be having sex on the wrong days.
Anyway, OPKs don't guarantee that you're ovulating, only temping can do that (FF has tutorials to help you learn about your body and your cycle and how to use the site). I am a horrible sleeper, so temping didn't work for me. FF will remember past charts and cycles helping you to pinpoint your fertile window.
Around my FW time, DH and I would have sex daily, and I would begin peeing on OPKs (buy Wandfo brand at amazon.com). We'd have sex daily until I started getting negative OPKs. We tried very hard to hit the 3 days before ovulation, day of ovulation and the day after ovulation (due to not temping, all of these were technically guesses based on positive/negative OPK results).
This system worked very well for us. I got pregnant on the second try in June, m/c'd in July. Got pregnant on the second try in late September/early October and here we are!
Good luck!