Good and bad days with Autism?

My 2 1/2 yr old has something going on. She definitely has sensory processing issues.. I dont know if she has Aspergers but i truly believe she has some mild form of Autism.. I have been told that kids with Aspergers dont have good and bad days, they just are who they are everyday. Ava is like that too but some days she is so sensitive to stimuli i dont know if this is the sensory disorder or if autism can have good and bad days..

Any thoughts? we are trying to figure it all out.. evaluations have all said different things. Aspergers, PDD NOS, anxiety disorder, sensory processing issues...