could i still be pregnant?

what are the chances of getting a period (a little lighter than usual but definitely a period) and negative pregnanacy test? I'm asking because people have told me that you can still have a period and be pregnant. it's all so scary to me and i literally sit on google scaring myself even more! so has anyone personally been pregnant while still getting a period and negative test? sorry if i sound silly but i'm young and stupid. 😒