contractions 5 min apart...but not feeling them?

Has anybody else been told they were having contractions 5 minutes apart, but they couldn't feel them? I was sent to labor and delivery today to be monitored for high blood pressure. While being monitored the nurse asked me if I was feeling any contractions and I said no. She then told me I was having contractions every 5 minutes but I wasn't feeling them?! Has anybody ever heard of this? Or experienced this? The nurse acted as if it wasn't a big deal 🤔