[jns]

Your nurse didn't explain things right. The 5th would be the 6th day of your cycle and the 6th would be your 7th. The graph I saw indicated that ovulation can occur on the 7th day of a woman's cycle although it is unlikely. Any day after the 7th in a woman's cycle until about the 20th day is a day in which ovulation is more likely to occur with the peak averaging about the 14th day. What was not explained is that sperm can live up to 5 days in the uterus and later the fallopian tubes. Some sources say 6 days but the sources that give the odds of pregnancy related to ovulation indicate that the second and third day after sex are the ones with the greatest odds and after the fourth day there is little chance of getting pregnant. So on the 7th of June, you would be on your 8th day and it would be the 2nd day after sex. On the 8th of June, you would be on your 9th day and it would be the 3rd day after sex. On the 9th of June, you would be on your 10th day and it would be the 4th day after sex. On the 10th of June it would be unlikely any of the sperm could cause pregnancy.

You would have had to ovulate early in your cycle, but you could have gotten pregnant from sex on the 5th of June. I think that this is a more likely scenario than a failure of the emergency contraceptive.