Now i'm not sure if this still applies but it may well do.
If you are unsure about your HCG you can in theory check if it is indeed HCG by making it up as normal and then placing a some on a pregnancy test, if its positive i.e. pregnant, you have real HCG.
The reason for this working, in theory at least is due to HCG only being produced by the developing embryo to in a simplified explanation keep the corpus luteum producign progestrone to prevent the embryo being killed. As HCG only appears when a fertilised embryo is present then pregnancy tests work off of this to gauge if a woman is pregnant or not.

just thought i'd share
If you are unsure about your HCG you can in theory check if it is indeed HCG by making it up as normal and then placing a some on a pregnancy test, if its positive i.e. pregnant, you have real HCG.
The reason for this working, in theory at least is due to HCG only being produced by the developing embryo to in a simplified explanation keep the corpus luteum producign progestrone to prevent the embryo being killed. As HCG only appears when a fertilised embryo is present then pregnancy tests work off of this to gauge if a woman is pregnant or not.

just thought i'd share