Only 17...could be pregnant

Missed my period last month in October I thought I was pregnant but then I ended up getting my period nov 1st it wasn’t a heavy period like it usually is but I still wasn’t worried. My period cycle varies from 35-40 days it’s never on the 20ish days. Hasn’t happened in years. My cycle is irregular so I never know when I’m ovulating. And Monday I got light pink spotting. I had nothing on Tuesday and then again this Wednesday I had light pink spotting I thought my period was coming but it didn’t. Could I be pregnant ?