Given the data you provided, your last menstrual period started on 6th August, 2008. If you use the standard formula to calculate the delivery date (plus 7 days, minus 3 months of LMP), it turns out that the most probable term of delivery might be 13th of May, 2009. But this formula is used for women with a 28-day-cycle, which is not a case.

If a menstrual cycle is 32 days long, than the most probable fertile day of the ovulation is (32-14=18, only if the cycle is regular) the 18th day from the start of the last menstrual bleeding, plus/minus 2-3 days (from 15th-21st day from the beginning of menstruation might be the most probable fertile days for you, under one condition: that your next bleeding would have started again 32 days after the beginning of the previous one on 6th August (and, unfortunately, we could never be positive about this!).

Also, we have to take under consideration the facts that spermatozoa might live in the vagina for 24-72 hours after ejaculation as well as that there might be a few alive spermatozoa in the pre-ejaculation lubricant liquids, expelled during a sexual intercourse.

From all of the above, that actual intercourse during alcoholization might not be the actual conceptual one, but one could never be 100% sure about this.