On August 13th in the evening, I started bleeding (like my period). On…

On August 13th in the evening, I started bleeding (like my period). On August 14th, it was more abundant but not too much. It all ended. One doctor said that she doesn't see two lines on the test (she did it on August 6th). That she should do an ultrasound on day 11-13 of the cycle. A second doctor asked me to have a blood test for hCG, which is 1.25. So I am not pregnant (I had an ultrasound on July 24th; they told me there was a yellow body 16 x 3 x 14 mm). Could I have a cyst? It was with me six