I am 4 weeks late with my period and have taken 2 home tests and they were negative. I also took one at the doctors office and it was negative. I have not done a blood test. I started sprintec in July and haven't missed a period since it's like clockwork every month. My breasts aren't sore like they were with my first but I have had some cramping in my stomach. No new diet or workout regimen. I am 23. Please advise