please read need advice

I posted a bit ago cuz I’ve been worried about the possibility of being pregnant I’m pretty sure I’m not because we used protection ( it fell off a couple of times but never while he was inside me)and I took a plan b but my period is supposed to be tomorrow according to the app and I’m having no signs of it coming and I’m feeling some what nauseous but it is sick season here so I could just be wrong I also took a lot of tests but I’m not sure if it would just be to early to tell but I’m scared I just want some reassurance as I just started college and do not feel ready