Hcg retest

Had to get retested for my hcg on Monday and wednesday this week to make sure hormones were rising.

First lots was 800. Mondays results were 48000 and yesterday was 56000. Is that normal? I did have the test about 45 minutes before my last one. Will that make a difference?

Doc just called and said she confident that everything is fine and going they way it should be and we should be able to see baby on during ultrasound, as last time I went in we could only see yolk sac. But we should see baby and heart beat now.

Anyone had this happen to them?