Have i given my son autism by having a lot of ultrasounds and using pitocin?

No worries: Hypothetically anything is possible, but NO, sound waves, ionizing radiation (such as nuclear), and electromagnetic radiation (such as from cell phones and microwave ovens) have not been shown to cause autism. Our society's increased exposure to modern technologies such as cell phones has occurred by COINCIDENCE at the same time as a rise in "autism diagnoses."