Yes, definitely do it first thing in the morning! I was so anxious that i did it at night once and got a very faint line which made me panic. Morning urine has the highest hCG concentration, so it gives the clearest result.
It is always recommended to test in the morning for accurate results. But if you missed your period, the best thing is to call your gynac. They will guide you on when to do a blood test to confirm.
Morning testing is best because the hormone levels are most concentrated. Since i had thyroid issues and irregular cycles, my doctor advised me to wait a couple of days after my missed period and test in the morning, and then follow up with a clinic visit.
My hospital coordinator told me to always use the first morning urine sample for home kits. It's more accurate because it's concentrated. If you are confused, you can even request a home-collection beta hCG blood test through your hospital lab.
Haha yes, morning pee is like gold for these test kits! If you do it later in the day after drinking 4 cups of chai, the line might play hide and seek with you. So have some patience and test first thing tomorrow!