HCG levels

Good evening,

Ten days after ovulation I got a positive pregnancy test on May 19th. On May 23rd I started really lightly spotting. I went to the doctor and he ordered HCG tests. I got my first HCG lab work done on May 24th. My levels showed 1137. I just got my second test done and it shows my level at 1354. My light spotting stopped yesterday. I have back pain and light cramping still but it comes and goes and is very light. I also sometimes feel tightness almost like movement but know it is too early to feel anything. This is my second pregnancy. With my first I had to be on progesterone until 13 weeks. My current doctor doesn't believe in progesterone so he has not tested my levels or prescribed it. Has anyone else had their HCG level not double and was able to give birth to a health baby?