HELP ? ! ? ! ? ! : (?

i had a plan to stay under 600 - 800 cals todaay. i had 8 cucumber slices, 1/2 cup of fiber cereal and i jusstt atee a slice of pizza from pizza pizza ! you know how big the slices are and howw greasssssy it iss, can you please tell me if im going to gain weight because off what i ate today? and how many calories were in that piece off piizza? PLEASE :(