I took like 2 or 3 sips of a beer around 6 pm and now have a headache. is it safe to take an advil ?

Advil ok: Drinking alcohol with Advil is not typically advised given you may have some stomach discomfort from the increased stomach line irritation. However, 2-3 sips is not very much so taking some Advil 200 mg (i.e. 1-2 pills) for your headache should be fine. It would be advisable to take it with some food to help prevent any stomach irritation.