A lot depends on how old you are, if you have other medical conditions, if you are taking medications, are stressed, etc. and if the palpitations are associated with other symptoms suggesting inadequate heart function as a consequence. These symptoms are typically things like lightheadedness, shortness of breath or chest pain/tightness. My advice would be to discuss this with a doctor (sorry, no nurse can help). Typically, the doctor will take a careful history (things I mentioned above, and more, like family history of palpitations or sudden death) and physical exam, run some blood tests looking for things like anemia or hyperthyroidism, order an EKG and then set you up with a Holter monitor. Palpitations at a young age are relatively common, so no need to panic, but I would arrange to see a doctor as soon as you can. Of course, if the palpitations persist, definitely go get seen now.
One easy thing to do is to take your own pulse (either in your neck or your wrist). Count the number of beats for 60 seconds to get your pulse. If your pulse is higher than 100 beats/minute at rest (and especially if it is really fast, like 150–200), then you should consider getting checked out ASAP.