Faint + then a Negative

I took a Clear-blue test on 09/27 and it gave me a faint positive; then I took another one on 09/28 and got a faint positive again from another clear-blue that i bought brand new from a different store just to be sure it was not a defect and then I bought a First response from a different store and it gave me a negative. My breast have been sore like crazy but that it. O did i mention i have irregular period but my last menus was Aug 31st and we have not been protecting ourselves... please help what does this mean...