Pregnancy tests and first morning urine

So I am 12dpo, I didn’t have any pregnancy tests this morning so I went and got some while doing errands. I went pee for the first time about 9:30 this morning and not again until 4:00 and I drank a half a cup of sunny-d and a Oreo milkshake, I don’t know if that would have diluted it a lot. But anyways, it was so clearly negative. Lol. So my question really is how much more effective is first morning urine? If it came out that negative could it still be positive say If I tested in the morning? I may not test again until Monday if AF doesn’t show. I don’t have any AF symptoms that I would normally have, but I do have some other symptoms that aren’t normal for me.