Could I be pregnant!?

I'm really worried that I could be pregnant. On the 18th (October) my regular period had ended, and I ended up having sex the 24th-26th. On here or states that I was 33% fertile that first day. I ended up having a weird 3 day spotting on November 7-9. And I'm worried that I could be pregnant because I haven't had anything happen since then. I've been breaking out in acne since then.