Need some answers on symptoms of miscarriage please

Yesterday spotted brown. Today a smear of brown blood on undies. Went to hospital as directed by MD and the urine test was negative bcuz im too hydrated so i took out a test i had in my purse and it was positive then a transvaginal ultrasound they couldnt see too well. Id be 6 weeks tmwr. Approximately. My first on apt is next wed. They said its 50/50. Miscarriage OR just very early pregnancy. I have had nausea, breasts tender sore and blue veins. And a cramp feeling like stretching. They advised me to test every morning until i see the ob on Wednesday. Can anyone elaborate similar symptoms please?