1st positive

I got my first positive test on Sunday and confirmed another urine test at my doc office on Wednesday. This was day 20 after missed period. I took three other tests earlier this month and they were all negative. I don’t have any symptoms except low back pain and some small cramping every once in a while. Plus some worry that I’m not actually pregnant or it’s etopic or a chemical pregnancy. Should I take another test? Or just calm down and wait for blood work. Anyone else have this?? Help please