Hello and thanks for your query. I shall make an effort to provide you with good professional recommendations specific to your questions. Even though rare, pregnancy can occur if you have intercourse during menstruation. After consuming the post coital pills, your next period should start within the next month, although it might come a few days early or late. Post coital pills are highly effective taken within 72 hours of unprotected intercourse. It is difficult to diagnose pregnancy with only symptoms. Symptoms do occur. But it is difficult that you will get them very soon. One of the earliest and simplest way to know that you are pregnant or not, is by using, urine pregnancy test. Most experts advise that you should wait at least one day after your missed period before taking a home pregnancy test, though waiting a week is considered best. This can be tough when you are anxious to find out if you re pregnant, but waiting allows for a higher degree of accuracy when taking the test, as hCG levels rise rapidly in pregnant women. It s best to do the home pregnancy test first thing in the morning, when your urine is most concentrated and hCG levels are highest. So I advice you to perform a test a week after missed period and with morning sample of urine. This test kits are nearly 98% accurate, so reliable. With transvaginal ultrasonography, the diagnosis of pregnancy can be made earlier by 4-5 weeks gestation Yet again, I duly appreciate your query to me, I do hope that you have found something useful to help you and I shall be glad to answer any further apprehensions. Sincerely,