Late Period... Please Help

I am almost always on time and I'm 4 days late so far. I don't think I am pregnant, but there's always a slight chance. We haven't had sex in over 2 months (protected always), however he will sometimes lie on top of me and rub against me with just underwear on. If I don't get it in the next 2 days, should I take a test or is that too early? I'm definitely a worrier so I'm freaking out. I'm in college and it's finals week so I've been super stressed and eating like crap, or not being hungry to eat certain meals for the past week and a half. What should I do?