Late Period and Phantom Pregnancy


So my period is 3 days late and I’m kind of in denial about being pregnant. My friend who is pregnant said she did not have symptoms until 2 months after she was pregnant. Me on the other hand , I’ve been feeling lightheaded and nauseous. I’ve been cramping but not my normal cramps. These are less severe. I know the only why to find out is to get a pregnancy test and use it. I am going to the pregnancy center tomorrow morning. I just don’t want to make a fool of myself if I’m not. I was wondering could I be having these symptoms because I’m stressing it and it be a Phantom Pregnancy and it’s all in my head or I could actually be pregnant? Is it possible to already have symptoms at 4 weeks ? I’m stressing, aren’t I