What Causes Delayed Period With Negative Pregnancy Test Result?

Hi, I am Debaasrie, my LMP on 3/10/2011. I did follicle study on 14th & 15th oct. Doctor reported left ovary has 1 follicle on 12th day (14/10/2011). Next day on 13th (15/10/11) she said it ruptured. My hubby was not with me on that day. We stayed together at noon on 17/10/2011. But My peroid is now missed. On 35th day (6/11/2011) my preg. test was neg. I am confused. I have no PCOS. What can I do now? Will I take some med. for period? or Wait for some day & again test? Is there any chance of pregnancy?