M.W.
Wow. That sounds really strange for the doctor to say, "either that's a baby or your period......." I would go to a different doctor next time.
Anyway. Just relax and try not to think about it for the next week. Time will give you the answer you are looking for. As the previous poster said, you can keep taking the early pregnancy tests but they are not as accurate before you actually miss your period. And they are SPENDY!!!