Am I getting my hopes up?

Hey guys, I'm new here, I took a test last week and it was positive I took another test the next day to confirm and it was negative, but it was also a different brand, I have a doctor's appointment Wednesday to find out for sure if I'm pregnant, do you think it could just be a chemical pregnancy? Trying so hard not to get my hopes up, but getting really excited! The only symptoms I have had is heartburn, just yesterday my breasts started to get sore, and a few cramps for about a week.