Confusion in pregnancy. Should i do now?

I'd unprotected sex (but didn't got sperm in vagina) three days on different dates and missed my periods. My periods were 10 days late. I am feeling too likely to be pregnant. When I did test than there was no clear result, there wasn't even a one line which was clear, it were faint and pinkish everywhere. But today I got spotting and very little bleeding as compared to my periods high blood flow. i'm bleeding dark brown instead of red. And in that bleeding it's too much bad and weird smell whether it's never happened with me ever. I'm confused, it's my periods or it's my early pregnancy? Someone told me that I might still be pregnant, in early pregnancy there can be bleeding or spotting in early three months. Please help me, I'm too confused that I'm pregnant or not. Please explain me, what should I do now?