Hello,
This is Dr. Papaqako answering your question.
Thank you for posting to HCM.
Alcohol does not decrease the effectiveness of birth control pills, like
Microgynon 30.
However, what drinking alcohol can change is the likelihood of missing a dose of the pill because of intoxication, due to an intoxication-induced impairment of judgment.
Also, the hormones in birth control often reduce the liver's ability to metabolize the
ethanol in alcohol. This leads to higher blood alcohol concentrations in ladies on the pill and intensifies the effects of intoxication. In plain English, you might get drunker quicker.
About your second question, the answer is yes, you can take it at 9pm. Although, taking the pill with 1-2 hours late, is not a difference that can affect the pill's effect.
Hope this helps,
Take care.