I started using "period" underwear a few years ago, but until I found Knix, I felt like I was wearing a diaper. Knix has the best leakproof underwear around, and I have tried four brands to date.
I have found that Knix is discreet enough to wear daily, even when I don't need the extra protection. It doesn't leave panty-lines, so they have become my go-to underwear month-long.
They have an incredible return policy also, although I have rarely wanted to return anything.
Comfortable, great-looking, great-wearing all month long! That is a value!