Scared

Hello! About two - three days ago i had sex. We went unprotected and used the withdrawal method. I’m a little paranoid though due to the idea of pre cum and other little things. I was not ovulating during the time of conception but, there are always possibilities. I was reading through the internet and symptoms of pregnancy don’t show till a week after. My period is suppose to start in a couple of days. Do you think i’m overreacting or have any advice?