Evap lines appear and usually stay there once the test has dried, so they're usually seen long after the time limit is up - they're colourless and thin usually. If the lines appeared quickly it's unlikely they're evaps, especially on two tests. I've used hundreds of those strip tests and never had one!
I know how you feel about being scared to test in case it's negative though - and you want that hope and excitement of possibly being pregnant to carry on... but even if you tested and it was negative it wouldn't mean you're definitely not - it could still just be too early for a test that's not quite as sensitive (you don't get any more sensitive than those strips) x