Menstruation :: Brown Discharge A Week After Ovulation Should Have Been

Last month a week after my ovulation should have been, I had brown discharge for a week. Then a week later my period was due it didn't come. Now its a week late. The negative hpt. My nipples became sore first day of missed period, now my breasts are very sore. I've always been very regular 28-30 day cycle. My fiance and I are not ttc but not the most careful. Last month we had sex but nowhere near ovulation we used the pull out method. Two days before my period was due we had unprotected sex. Im 28. I don't take any medications. Could this be thyroid, cysts, or pregnancy? Should I see the ob right away or wait for another missed period. Also my breasts have never been sore after my period was due only before.I also felt feverish a couple of times. I am now getting nauseous and dizzy. I called the ob this morning and she said they suggest waiting two weeks after a missed period before taking another pregnancy test. What seems more likely pregnancy or cysts. is it unlikely I'm pregnant