Hi,
i'm sorry I have only just read your message.
I would suggest you get a blood test as this will show definitley if you are pregnant or not.
My friend had the same thing did a few urine tests all showed negative she went to the doctors asked for a blood test and it came back positive.
This happens if you are only just pregant the hormone level sometimes isn't high enough to show on a urine test but blood test will show immediatley.
Hope this helps you.
Good luck!
And if you are pregant congratulations!!!