Help 😩

I had sex the 13-14 (on my last two days of my period) of September and then the 26-27 of September and my period was supposed to come October 5th. It was late a total of 4 days before I took a pregnancy test and got a faint positive on the 8th. 2 days after the positive pregnancy test on the 10th I started bleeding with some kind of brownish discharge, it was light the first day and got a little heavier the next and today which will be 3 days of bleeding it slowed down a lot and is soooo much lighter. I have a doctor appointment tomorrow at 9:10 but will they be able to get an accurate test with the blood and everything or should I reschedule it but I really wanna know what's goin on.