Period Due on 27th

I was due on the 27th & still haven't started. I haven't tested yet because I've been lightly cramping since the 25th so I keep assuming I'll start any day now. I'm 4 days late now & that's never happened to me before. I'd like to test but with me cramping on and off, the sore nipples, and me being emotional, I keep convincing myself I'll start soon. Thoughts?