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Vitamin A supplement is considered high-risk during pregnancy and causes congenital disabilities. But the dose and duration you consume have a substantially lower risk. But the risk regarding the effect of vitamin A cannot be completely ruled out. Regarding vitamin B12 and autism, most research has shown that consuming excessively high levels of vitamin B12, more than 20 mg, in women with higher than baseline levels of vitamin B12 can result in fetal autism.
The dose you have taken is safe, and if there were any excess, it would have been washed away. However, I am not aware of your baseline B12 levels. If there were even a slight deficiency (as it exists in most women worldwide), then the vitamin B12 supplement would not have done any harm. It would be safer to consult a fetal medicine specialist to get additional scans which would help determine if there is any effect on the fetus.
I hope this has helped you out.