Im curious and worried

Hi everyone is there chance of not being pregnant after using a pregnant test kit testing positive? Im found out im pregnant with a test kit n schedule a gynae immediately 2week later which i assume to be 8weeks..but will that still be chances im not pregnant ? As i dont really have much symptoms. Only sore boobs n mild cramps, tiredness...somedays dont feel anything at all...somedays extremely tiring. But i dont have any nausea like many. Is it good or bad?