Is there any possibility of pregnancy with extremely light spotting?

My husband and I were physically intimate on the 17 and that was the third week that I was wearing my patch and yet since then we haven’t been physically intimate and I just took my patch off on Friday night. I was spotting on Saturday night, Sunday morning and last night and then early this morning.

When it’s the 4th week is my off week for me to get my period and so yet I’m not sure if it’s a sign of pregnancy or if it’s actually making my period extremely light.