yesterday in my 2004 acura tsx the "d" light on my dash was blinking, and then my check engine light came on for a second. today when i drove my car it was fine nothing was on and nothing was blinking.What do you think happened?

 

Maybe just a glitch but I'd be paying attention to anything that may be out of the ordinary - specifically transmission related (i.e. noises, harder shifts, slower/lagging shifts). If you get it serviced by the dealer, have them check for a code next time it's in.