last time I had sex was 2 months ago 4 days after my period then I got my period (or so I thought) when I was supposed to. It was 5 days; first day was light, second day medium/heavy, third day medium and last two days were light. I did not get my November period and am now a little over a week late. I recently been feeling some symptoms like nausea, headache, cramping and constipation. Today my nausea was not quite there but my stomach started getting tight, especially under my ribs. Am I pregnant or is it ibs?