Hello girls I wrote to my gynecologist and told her to come on the 7th…

Hello girls I wrote to my gynecologist and told her to come on the 7th day of my period But today it's only 4 days and I'm worried The periods are very dull and brown For 1-2 days they were black I explained to the doctor that she said to come on the 7th day for an ultrasound and a smear test But she didn't explain why this is happening Can you please tell me if anyone has had this happen? What happened in the end? Can you please tell me I'm really worried