What Causes Delay In Periods,abdominal And Chest Pain?

Hi! I am 30 year old ,I am married and have two kids younger one is of 18 months.I was expecting period at 17th of this month but till now I did not get,3 days before I had pain in abdominal,back and right side of chest and even there was discharged of white mucus.Will this be a sign of pregnancy .And 3 weeks before I stop feeding my baby in morning .Two of my pregnancy I was as diabetic patience.