Combination pill and no period help!!

I’ve been on the combination pill for a year now and take it at mostly the same time every night. I had unprotected sex a lot of the month but he pulled out every time. It is my placebo week this week and I have yet to get my period, however, I had spotting for like an hour one day and have had cramps and a little nausea. Is this a sign of pregnancy? I have been very careful with taking my pill so I am confused and very worried