If you had unprotected interourse two weeks after your period, there is a high likelihood that you can get pregnant. (Since you must have had sex on Day 14, which is usually a fertile day for people with regular cycles.). Women in childbearing age has 20-25% chance of getting pregnant every cycle. And you are at a very fertile age (Below 25). So there is about a 25% chance that you could get pregnant.
But only a pregancy test can actually find out if you are and it is now too early to take a test. Pregnancy symptoms do not show up that early and most of the pre-menstrual symptoms mimic preg. symptoms. So what you are experiencing could just be progesterone related symptoms.
You may have to wait in order to take a test. Ideally, you should take the test on the first day you have missed the test. However, there are very sensitive tests these days that can detect the preg hormone much earlier.