Is it true that NyQuil can cause false positive pregnancy tests?

Ok so the other day I randomly took a test out of the blue and it was positive. I was floored. We had sort of stopped trying, but my period was late, so I took one anyway. I immediately went out and got more tests and took them all. All positives. Now I had taken NyQuil the day before because of a bad cold. Could that have caused a false positive? I heard that was possible and I'm hoping that isn't true because we already told our parents and siblings.