Lemondrop are you using a different brand test to yesterday? - Different tests have different sensitivities, so some will show a Negative result when you get a positive on another type.
Also, as Wobbles has mentioned, this early in pregnancy a diluted sample can give a negative result. Always make sure you are testing with urine that is very dark in colour. Pale urine is too diluted to detect HCG at early gestations.
-As for the bleeding, it may be nothing sinister as many women will have some degree of bleeding during their pregnancies.
Really hope everything is ok.