I got off of Yaz in December 2008 and had my period twice that month. I had a normal cycle in January and another in February. Well, I was expecting to receive my period in March with a 28 day cycle and I am currently 18 days late! I have taken several HPT and a blood test but all show negative. I'm not stressed either. I have never been late before YAZ. My husband and I are TTC and i'm so confused on what's going on with my body. Has anyone had a problem like this?