Period 2+ weeks late, Neg Preg Test ??

I have been trying for about 6 months to get pregnant and have been using the OPK tests. On June 10th I took the OPK test and came back positive for ovulation.. usually I get my period exactly 16 days after the OPK tests positive.. it is now July 12th and I have not got my period yet.. my cycle is almost always 32 days. I had sharp back pain on the day my period was due and a lot of clear discharge for a few days later. I haven't had any nausea and have not been excesively tired. I have taken 2 pregancy tests and they both came back negative. I am confused.. am I pregnant? How long should I wait before going in for a blood test. I have quit alcohol and smoking and taken folic acid everyday just incase.
I have never had any issues with cysts or other female problems.
I REALLY hope I am pregnant.

Any input would be help.. my husband and I feel very alone with all this.