It looks like a pre-o dip to me. Alcohol raises your temp & nurofen lowers it, so they would most likely cancel each other out. I wouldn't pay any attention to the opks. Your LH surge may have been really short, so if you did the opk at the wrong time you would miss it. Sweating will also lower your temp. Is there any chance you have issues with blood sugar levels? Alcohol can sometimes affect your blood sugar levels. Another cause could be insulin resistance associated with PCOS. A sudden surge in insulin production could cause your blood sugar to drop suddenly, which could cause you to break out in a sweat, which will lower your temperature.