Positive Pregnancy Test, Then Negative Test 3 house Later?

Hiya. I had exactly the same thing with the tests! I tested with fmu and i got a positive. Then when i tested again in the afternoon it was negative. Same as you i went wee just before therefore not using concentrated urine which is so important when detecting an early pregnancy as the hormones are still so low. That was at 11dpo. I'm now 6 wks pregnant! Remember even 11dpo is early to get a positive as it takes 7 to 10 days to implant then another couple of days 4 the hcg to build up so it can be detected. I really don't know about the shot though honey but it sounds like good news to me! Good luck x x