Freaking out!

My period is 4 days late. Periods aren’t always going to be so accurate. However I’ve been really stressing about it. I also have a yeast infection which is just perfect..... my mom scheduled an appointment for this coming Friday and I’m so scared that I’m pregnant. I took a test two days ago in a store bathroom with my bestfriend 😂, it says it’s negative. But Idk if I should trust it. Should I take it again? And of course my mom called the office and told them I wasn’t sexually active, so 😖. And if she finds out I am or anything I will be murdered and my boyfriend and I will never be allowed to see each other again. And he’s such a sweetheart, he’s been stressing about it too. He’s been checking in and supporting me so much. Ahhhhhhhh freaking out