Positive or negative

Emilia

I took a test last night and it came out negative. I accidentally left it on the sink in my bathroom and my husband seen it 5/6 hours later and it was clearly positive.

Now I know the box tells u do not read test results after 5-10 mins from use. But this has never happened before.

Is it possible to be pregnant but to early for test to pick up right away.

Or will my metformin give a false result