kleptopigdog

I was out running errands all day today in my 94 automatic . Some time this afternoon something didn't feel right and i noticed i lost first gear.Car ran fine just wouldn't down shift into first..Taking off slowly it felt like it was in first for a sec then went into second. I did a hard launch and you could clearly tell it was in second .Tried a couple of 25 mph stomps and it didn't downshift in O.D. Any suggestions ?