period or ?

I am due my period within the next upcoming week. Although this has been a pretty weird month for me. I've been having pains on both sides for the past three weeks and bad stomach cramps. I've also been having very bad headaches which I never get! I've also had horrible smelling discharge, like I notice the smell when I'm just sitting down not even on the toilet!
I had sex on the third day of my period- unprotected. I was on ponstan at the time as I suffered from very bad periods and I find it helps ease them and also have a lighter flow. My period finished 2 days later.
Today when I went to the bathroom after major cramps and I found the tiniest amount of blood like nearly unnoticeable- it was like a red colour?