Hello and thanks for your query. I shall make an effort to provide you with good professional recommendations specific to your questions. It is difficult to diagnose pregnancy with only symptoms. Symptoms do occur. But it is difficult that you will get them very soon. As you have missed the OC pills and also you had unprotected intercourse, you can become pregnant. Plan B is for emmergency and should not be used routinely. As a drop of pre ejaculate is enough to make pregnant, hence I advice you to consider one or the other method of contraception if you don t want to get pregnant. It is better to be cautious. 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. I advice you not to take any medication without consulting doctor, as all medications are external substances and they have their own side effects. I do hope that you have found something useful to help you and I shall be glad to answer any further apprehensions. Sincerely,