Does low hCG level indicate ectopic pregnancy or miscarriage?

Hello doctor,

Before a week I went to the hospital and I found out that I was pregnant with a hCG level of 23. The next day, I started getting cramps on my lower right side stomach. Four days later, I got two transvaginal ultrasounds and nothing was found in the uterus, or anywhere else. So I was sent to the hospital again concerning an ectopic pregnancy or possible miscarriage. I got blood tests done, and they told me that my hCG levels went down. So, they ruled it out as a miscarriage or I was in the process of losing it. So on the next day, I went to my doctor, and she told me that she does not understand why they said to me that my levels went down as they went up from 23 to 100’s, so she said it could be an ectopic pregnancy. I got more blood test done, and I came to know that my hCG levels are going up but very slowly. I do not know what is going on. First, they said it was a miscarriage and now something else. I need answer. This is my first pregnancy.