18 and might be pregnant

So we didn’t use any protection... not even the pull out method and I feel very off and just strange and I can’t get a test because if I’m not pregnant I don’t want my mom to have to stress about nothing, I’m not sure when my period is supposed to start but I know it’s anywhere from today to a week. What were your first symptoms and how did you find out you were pregnant?

(P.s yes I know what I did was stupid and if I am to be pregnant I’d be more then happy and if I’m not we’re going to be a lot more careful until I graduate)