What Causes Light Spotting, Cramping, Nausea, Heartburn And Tightness In Stomach?

i had a period on the first but it was a medium flow and light spotting the next two days.i started cramping after with no bleeding. i been feeling sick. nausea, heartburn, headaches. have tightness in stomach along the sides and a little at my lower stomach. also sorness in my breast. i took two in home pregnancy test they both came up negative. should i wait till next month and take another or make an appointment with an ob now