Could I be pregnant but just have low HCG?

I have missed my period. I have had TONS of symptoms but I did get a negative blood test. The only reason I'm not sure if I believe it is because my sister and mother were not able to confirm any of their pregnancies until almost 3 months in because of the their hcg levels being so low. Has anyone else ever experienced this? Could I also have the same issues with hcg?