16 year old who has regular periods noticed bloody discharge today. had period about 2 weeks ago. is something wrong or is it just spotting?

Pregnant?: Pregnancy is a common and important cause of bleeding like this - If there is any chance you could be pregnant you will need a pregnancy test. If you are not pregnant and this does not persist it is likely not of major consequence - probably due to immaturity of your hormonal signaling. However, if it persists you will need evaluation.