What Causes Delay In Periods,cramps And Breast Tenderness?

i am 5 days late and i have cramps as if my period would be coming. i have not had morning sickness, or breast tinderness-even though when i do get my period my breast sometimes get tender. I am very gasey. We have been trying for 4 years now and were unable to concieve due to my fiance having low sperm count! Do you think i could be pregnant?