Am i pregnant? help!

Im quite young and my boyfriend and i started having sexing recently. this would be my second period since having sex and it usually comes like clockwork. The last time we had sex i was only a day late but it still worries me. We have always been safe and used condoms since my mother is quite conservative and would not want me on any other type of birth control. her cycle and mine come almost always at the same time and she asked if i got it today and all my apps and calendars say im 2 days late. How do i know if i should be stressed or im just nervous?