Thank you for your query at DoctorSpring.com
I am Dr. Jaydeep and I am pleased to assist you.
The amount of whisky you had is not going to harm the baby in any way, so please do not worry.
When pregnant women keep drinking or binge drink, there will be lesser absorption of vitamin b12 from the intestine. This hampers the organogenesis and may result in congenital malformations. One such isolated exposure will cause no harm.
Feel free to discuss further,