my boyfriend and i had a accident we used a condum but it broke, he went to pull out fast but does not think that he pulled all the way in time, i had just finished my peroid the day before, i went and got the plan b pill the next day and took it 14 to 15 hours atfer the accident, a week later i bled lightly for three days, but have not had my peroid yet it is due next week, is this normal? what are the chances i could be pregnant??