So as of today I am 8 days late. Yesterday with first morning urine I took a dollar store pregnancy test-it came up positive and this morning I took a First Response with first morning urine and it came up negative.Is this common and could I still be pregnant?

Believe it or not, cheaper tests tend to be more sensitive and can give results sooner. Here is a great site that explains it all: http://www.peeonastick.com/

A false positive is very rare. False negatives are very common.

So, if you got a positive result, I'd say congrats. :)

The accuracy of an HPT increases exponentionally the longer you wait after missing a period. In the first week its less than 50%, increasing to over 95% after 2 weeks.

It is very likely you are pregnant, I would wait about 6 more days and do another test. And/or go to the doctor for a blood test to be sure.