So confused!!!

Ok so now I'm 2 days late for my period (which is pretty common for me because I'm pretty irregular.) But for the last week I've been experiencing period symptoms-my boobs hurt, I'm cramping, my back hurts etc. My period just won't come? I know I'm not pregnant because I haven't been sexual active this month and I got my period last month, so I just don't understand what's going on.