low hcg levels???

casey

so I just had my levels tested yesterday. my progesterone is 22 but my hcg is only at 90....this app is estimating me at 4 weeks 6 days. the chart I'm using shows that it's possible that I could be between 4 and 5 weeks but that my levels would be low....should I be worried??? has anyone had low hcg levels through out their pregnancy and still went on to have a full term pregnancy??