Anyone had low Hcg and it not double?

Alyssa • Mommy 💖 trying for #3💗 Baby #2 is in heaven💙 Married to my best friend 💞

So this Saturday my Hcg was 29 and Tuesday it only went up to 39. My doctor says it’s probably not viable have any of you ladies experienced this? I’m going in today but just don’t know what to expect