Negative serum HCG with elevated progesterone

Kalli
My last period was 10/16, cycle is 31 days. On 11/17 (day of expected period) my OBGyn sent me for bloodwork. My serum HCG was negative (<1) and progesterone was 23.6. Today is 11/20 therefore 35 days since my last period, I have never been late before. Ttc for past 6 months.  Could I be pregnant just really early? When should I do a urine test?