So confused

So it's been 12 days passed my AF arrival and I still have all the symptoms of pregnancy. My boobs are even getting slightly bigger. At 5 days passed AF arrival I took a blood test and it was negative. It's weird I'm never late. Like ever. So with all these symptoms and negative tests you can understand my confusion. I feel pregnant. I really do, so is there still the possibility that I am. I go for another appt tomorrow, just wanted to see if any one else went through this.