I found this online and hope it help some of ladies who have question about HCG levels.
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What can a high hCG level mean?
A high level of hCG can also mean a number of things and should be rechecked within 48-72 hours to evaluate changes in the level. A high hCG level can indicate:
Miscalculation of pregnancy dating
Molar pregnancy
Multiple pregnancy
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based on days past ovulation (DPO):
At 14 DPO, avg HCG level is 48 mIU/ml, with a typical range of 17-119 mIU/ml.
At 15 DPO, avg HCG level is 59 mIU/ml, with a typical range of 17-147 mIU/ml.
At 16 DPO, avg HCG level is 95 mIU/ml, with a typical range of 33-223 mIU/ml.
At 17 DPO, avg HCG level is 132 mIU/ml, with a typical range of 17-429 mIU/ml.
At 18 DPO, avg HCG level is 292 mIU/ml, with a typical range of 70-758 mIU/ml.
At 19 DPO, avg HCG level is 303 mIU/ml, with a typical range of 111-514 mIU/ml.
At 20 DPO, avg HCG level is 522 mIU/ml, with a typical range of 135-1690 mIU/ml.
At 21 DPO, avg HCG level is 1061 mIU/ml, with a typical range of 324-4130 mIU/ml.
At 22 DPO, avg HCG level is 1287 mIU/ml, with a typical range of 185-3279 mIU/ml.
At 23 DPO, avg HCG level is 2034 mIU/ml, with a typical range of 506-4660 mIU/ml.
At 24 DPO, avg HCG level is 2637 mIU/ml, with a typical range of 540-10,000 mIU/ml.
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expected HCG levels based on time after conception:
0-1 week: 0-50 mIU/ml
1-2 weeks: 40-300 mIU/ml
3-4 weeks: 500-6,000 mIU/ml
1-2 months: 5,000-200,000 mIU/ml
2-3 months: 10,000-100,000 mIU/ml
2nd trimester: 3,000-50,000 mIU/ml
3rd trimester: 1,000-50,000 mIU/ml
Non-pregnant females: <5.0 mIU/ml
Postmenopausal females: <9.5 mIU/ml
I think it could be twins, or it could be that she's a bit further along than she thinks. If you think about it, if the levels double every 2 days or so, and if a level of 1,000 is what her doctor considers normal for 4 weeks, then it would be about 2,000 at 4 weeks, 2 days and 4,000 at 4 weeks, 4 days. So a level of 5,000 would be about 4 weeks, 5 days.
Although, I know most women are usually just reaching the levels detectable by a HPT (25 - 100) around 4 weeks, so it does sound pretty high. Could she be 4 weeks from conception and not from her LMP?