Based on the available information, there is indeed a specific period during early pregnancy that is considered high risk for alcohol exposure. According to the National Institute of Health's (NIH) publication, "Fetal Alcohol Spectrum Disorders" [3], alcohol consumption during any stage of pregnancy can lead to fetal alcohol spectrum disorders (FASDs), but the risk is highest during the first three months of pregnancy. This is because the critical stages of organ development occur during this time [3].

The Centers for Disease Control and Prevention (CDC) also states that there is no known safe amount of alcohol use during pregnancy or while trying to get pregnant [2]. However, the risk of FASDs is highest for women who drink heavily during pregnancy [2].

The Drug Patent Watch's page on Alcohol does not contain specific information about the risk periods during pregnancy [1].

In summary, while alcohol consumption during any stage of pregnancy can lead to FASDs, the risk is highest during the first three months of pregnancy. It is recommended to avoid alcohol consumption entirely during pregnancy and while trying to conceive [2][3].

Sources:
[1] <https://www.drugpatentwatch.com/p/tradename/ALCOHOL>
[2] <https://www.cdc.gov/ncbddd/fasd/alcohol-use.html>
[3] <https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6876479/>