Spotting

I am on cd 30. Glow said I am supposed to start my period today. I have been only spotting though...I have had other symptoms sore nipples, stretch like cramping, and usually my period starts on day 28 or 29. Any body else spot this late and still be pregnant? Usually I don't cramp unless I get my period, but I have been cramping the last 3 days and still no full period.