HCG Levels..

So I had some light spotting on Monday, I called the OB & she ordered blood work to check my HCG levels. The number came back in normal range for where I'm at in this pregnancy (6w5d). But to be safe, she ordered 48 hour blood work. The level is supposed to double every 48 hours. I had the blood draw today (Wednesday) & the level did increase, but was not close to doubling. Anyone else experience this? I'm trying not to panic and wait til I hear from the doctor but everything I've read online does not seem positive 😑😭