diluted urine pregnancy test....

So on Monday I took a test and it was positive, it was my second urine from the morning after running some errands and it was pretty yellow. So today I took another one a few hours ago, like at 7 and the urine was more clear than yellow...so Monday's test was a tad darker than today, can diluted urine contribute to the darkness of a line? I'm 3 days away from my period.