I use fertility friend to input my temperatures and cervical mucus. It's a free site and I like it a lot. It shows me my luteal phase, average days in my cycle, and average day of ovulation. You can pay for the premium features of their site (which they often offer free preview days of) and those features would be pretty helpful when trying to become pregnant.
I use a Walgreens bbt and am happy with it. I only temp around 5-8 days before (suspected) ovulation, or once I see ewcm, until ovulation is confirmed.