Hi. I am on day 37 of my cycle and don't have my period. I have had cramps for about a week and a half. I last had protected sex may 10th and I took two at home pregnancy tests 2 days ago both negative and went to a doctors office and had them take one that also came back negative. The doctor said the results were accurate because I last had sex over 2 weeks ago. Is this true? Why do you think my cycle is so late? I have had a somewhat irregular cycle before but never this late.