Levels too low? 13 DPO

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Top one is 13 DPO FMU. Bottom is 12 DPO 7 pm. Went to the doctors today for the second time (waited 2 days) and the results were "Indeterminate". AGAIN. My HCG is doubling as I've looked at a test from 11DPO and it was obviously lighter. Should I be worried? (Went for a Blood HCG today) 

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