My periods have always been regular, lasting 5 days, with the first three days being very heavy. I have been having unprotected sex with my partner for four months. This month, I was three days late on my period, in which I found to be irregular, instead of my normal heavy flow, it was like a light brown spotting, I am now on my second day and I am bleeding a little heavier and today appears a redder colour. Could I be pregnant?

It depends. Depending on how old you are and how mmuch change your body has already been through. It could have been brown spotting before your regualar menstral. An irregular period just means it doesn't happen every 28 days. You period will never lookkk the same every month. HOWEVER you could as well be pregnant. All woman experience different signs of early pregnancy. I would say wait until the bleeding is over to test. If its in fact implantation bleeding a hpt has a better chance of deteting hcg after implantaion has taking place