Should I buy a test or am I overreacting?

I had my last period October 17th. My last day of unprotected sex was October 13th. My cycle starting on the 17th was normal flow, normal length (7days). I figured since I had a period a couple days after my last unprotected sex, I would be in the clear. However, I’m 7 days “late”. “Late” meaning I lightly bled for 3 days and it stopped. I woke up this morning with a pearly white, thick, discharge. I’ve been having weird dreams, and out of the blue decided to quit smoking for no reason.. should I be worried and test, or am I overreacting??

TIA