super scared

hey guys! I’m 17 years old and a senior in high school. on novemeber 15 I had sex and according to the app I was at a 27% risk to get pregnant. we used a condom but I’m not on birth control. I was supposed to get my period on saturday but I didn’t and the app said I would get it on monday and again, I didn’t. I’m not sure if i’m pregnant and I’m super scared. if I am pregnant my first option is to get an abortion pill because I cannot have a baby, but idk if I would even be able to afford the pill. I’m so terrified and I have no idea what to do. I don’t want to tell the guy though, is that okay?

I would really like to hear what you all have to say. thank you.