Is it normal to have not even a 12 hour period?

Intercourse was the day before I ovulated but, of course, much to my disappointment blood started flowing after 2 days of pink then brown CM. I'm not even spotting now (after 12 yrs of periods this is NOT normal for me. I would get major cramps the day of or before depending on the time of the day I get my period and then it's med-heavy flow the first few days and then it gradually dies down and it would normally last around 1 wk)! I barely had anything on the tampon when I woke up (730am) and my period started a little before noon the day before. I did go out to a bday party and had a few drinks but I didn't get drunk and this morning I was extremely nauseated (not a hang over cuz I didn't have a headache w/it cuz I always gets a headache w/a hang over) when I woke up and it was back and forth all day long! Has anybody else experienced this??