A question about ovulation calendars and actual ovulation?

Okay, I was wondering if you guys have ever used an one of those online ovulation calculators and found them to be accurate? The reason why I'm asking is because I'm almost 95% sure I'm ovulating right now. My LMP was 3/30/2009. It was 9 days late. It's a 32-day cycle. Anyways, according to all of these calculators, it's forecasting me to OV on 4/17/09 with a fertility window of 4/15/09 - 4/20/09. TMI COMING!! Well, yesterday, I spotted some brown discharge on my underwear. I tested CM and it was very scant. Earlier today, I noticed some more brown discharge and had some mild pain in the lower abdomen but it was sort of on both sides so I don't know. Anyways, tonight I tested for CM and got a TON. It was very clear, semi-thin, and stretchy. That, plus the brown discharge and the mild cramping leads me to believe I'm ovulating now. I don't chart or anything. But all of this is making me very weary about trusting these online calculators. Me and hubby BD'd last night and Friday night. I know they are just an estimate but I was wondering how accurate they are usually for you guys? Thanks so much and sorry this was long!