Need some insight

I have googled my heart out and google says I shouldn't be concerned. HCG was 60. Dr is adamant I am 5 weeks he claims ovulation was CD12 but I hadn't had a positive opk by cd14. I quit testing after that because I was tired of stressing myself and took a whatever happens happens cycle. On CD24 progesterone was 34, HCG was zero but fluid in my uterus. Dr told me to take a test if AF doesn't show. So 7 days later I got my BFP. Dr said my pregnancy is not viable. I'm not bleeding or spotting. I have mild cramping which he said was normal. What do I believe? Any enough gong stories. January makes 4 years TTC. I'm so lost and heartbroken. ?