Is this a positive?!

I did a pregnancy test last night and after a minute or two of waiting there was no result. I didn't look at it again until this morning and when I did, I could see a faint blue line?! I should have started my period on the 8th of December and still haven't.....not sure whether this is a positive or whether maybe the dye/urine has just settled overnight or something??? (If that's even possible) I've got another test which I will do first thing in the morning, but what does everyone think?!