Please help! I'm freaking out

Had unprotected sex last month (only a few strokes because I freaked out, guy didn't cum until I sucked him off). Got my period after that (about a day or two) no problems. But this month my period has been weird, I started spotting Sunday and Tuesday I got a heavier flow. Wed in the morning I had dark blood and it felt like my normal period but then it just got lighter. My flow is usually heavy and this month it's a lighter flow.

-I have no symptoms, no cramps, no nausea nothing

Could I still be pregnant? Please help

I'm going to wait two more days to take a test but I guess I just need reassurance