17 and scared

Usually my period comes a little bit earlier or on time than what eve predicts and I’m currently 3 days late and am having all of my period symptoms except for period blood. Last week I had my cheer camp and was exercising really hard, and I’ve been stressed lately, but I’ve also had a lot of unprotected sex in the last few months because I live in such a small area that it’s basically impossible for me to get access to condoms. I was just prescribed birth control and I’m supposed to start during this period but I don’t know what to do now. I do not want a kid now or for a very long time but if my parents found out I could be in an incredibly dangerous situation. The biggest problem is just that I can’t afford an abortion especially because I won’t be able to use our insurance