Good luck with the next test. It shouldnt matter too much if you use first wee of the morning, as you're so late that if you are pregnant then pregnancy hormone levels will be high enough for the test to detect in any wee you do.
Make sure you follow the instructions carefully, and if you're unsure of the result post a pic up here and we'll have a look and tell you if it's pos, neg or invalid.
Best of luck!