Am I pregnant?

Can combination pill make your perios late? I'm on combination pill for PCOS and I'm six days late. I've had protected sex with my bf before my fertile window For last two days I'm suffering from nausea and GI upset. The pill didn't suit me. I was having GI problems with nausea while I was taking it. The doctor persist me to continue with gastric medication. So did I. But now I'm six days late with moderate nausea.Am I pregnant or is it the side effect?