Is it possible to experience a delay in periods after having sex again after a long period of time?

My boyfriend and I had sex on the 15th of December before going long distance and then started having sex again on the 10th of March (all times with protection). According to glow, I am supposed to have my periods on the 28th. Additionally, I do have two midsems and an assignment due on the 10th of April..

Is a delay possible due to these circumstances?