Had 7 u/s in 7 weeks in first tri. 3 used 3d for parts. Worried about autism risk.

None. There is currently no evidence that ultrasounds cause or trigger autism.
The ultrasounds . Don't increase risk of autism. At 35, the risk of genetic errors increases; screening tests are done in the 1st & 2nd trimester.Ask what the specific concerns were about organ development. The structure that becomes the brain & spinal cord started forming 3 weeks after conception & other organs soon thereafter. Detecting an anomaly is easier ~ 16-18 weeks, so expect more fus's & other tests.