low HCG but rising

Hello ladies. I'm somewhere around the 6/7 week mark but my HCG levels are low and stressing me out. My first test last week was 248 and the test four days later only had me up to 410. So it hasn't doubled and is so low. I've had no bleeding or cramping and have been having symptoms, MS having to pee all the time, so tired and sleeping more then I ever do. Has anyone had anything similar to this with a happy baby outcome?