Ok so my periods are irregular but I do get them every month and usually I can tell when I am getting it. My last period was Feb16- 19, had unprotected sex Mar 5 and has yet to see my period. Probably a week later I feeling nauseous and getting headaches. I blew that off thinking it was nothing. Another week went by still no signs the my period was coming, but I am tired a lot, nauseous when I don't (and sometimes) eat, cramping here and there, and sharp pains running through my boobs here and there too. Took a HPT March 19, came back negative. I figured I would wait. Took another one March 31(today), came back negative and still no period.