Late period

Jessica
Does stress affect you're period? And if so, how severely? 
​I'm about 2 weeks late and I've taken multiple at-home pregnancy tests and they all say I'm not pregnant. 
​This past month has been one of the most stressful in a while. My anxiety is through the roof, my emotions are out if wack. Slowly I am starting to feel back to normal but the stressful anxiety lingers. 
​I am wondering if that is possibly the reason for not getting my period ?
​I am not on the pill and I do engage in sex with my boyfriend. So obviously there is a chance I may be pregnant. But I don't feel that I am.