i can understand your anxiety
first of all you should understand that pregnancy
test is suggestive not conclusive in nature.
there are other conditions like hormonal
therapy where it can be positive without pregnancy.
as far as other symptoms like morning sickness
etc are concerned they may or may not be present in a case.
the discharge is definately something to be careful about. but the qunatity and duration you have mentioned, it may not be the sign of some thing serious.
i would advice you to keep in touch with your ob.
too much anxiety or tension will not going to help but will make things worse.
take bed rest
, proper diet, be relax. may be later on USG will reveal the truth.
wish you all the best.