Since you're unaware that you're pregnant the first few weeks, what happens if you drank in that time?

Nothing "happens".

Only Americans seen paranoid about the whole "a single glass of wine will damage the baby" myth; other countries don't have a problem with occasional moderate drinking pregnancy.

As long as you weren't binge drinking all that time, nothing is likely to happen. If alcohol was so poisonous that a couple of beers could cause miscarriage then a) no one would drink it, and b) the need for medical abortion would not exist.

Nothing much. There isn't even an umbilical cord for the first couple of weeks.