That is strange that they were bold, now dotted?? I think the FF program must be losing its mind, LOL. I've had weird stuff happen with my chart at times lately, too.
I guess only time will tell if you did indeed O on CD 17. I agree, seems like an odd cycle this month. Hope next month is perfectly normal (and *ahem* hopefully you'll get a BFP and won't even have to worry about it for another 9+ months! lol).