My periods have been regular lately up until now. I am 8 days late. I had my usual signs of coming on but nothing has happened. I have had unprotected sex on a very regular basis with my partner for the last month. On one occasion I had slight spotting after. I have done a pregnancy test but it came out negative. Could it be wrong? I know something is different. I should also say that me and my partner had sex the day before and all through when my period was due. Not sure if that makes a difference??