I need some experienced advice.....

So I’m 18, and a senior in high school, and my boyfriend and i decided we wanted to have sex. We have been super careful, and always use a condom. I am not on birth control yet because my mother would castrate me and my boyfriend if she found out. How many of y’all have experienced scares when being careful? I have anxiety and so if I’m late by even a day I’m gonna have a panic attack. Do i have reason to be this scared?? Plz don’t judge or tell me to tell my mom, because i already plan on telling her eventually. I just need some advice from girls with more experience than me. Thank you!!