When to test after missed period?

Hey everyone I want to start by saying thank you to the people who have commented on my posts. This is the first time trying for kids so I have no clue what I'm doing. Now to my question...

when Is the best time to test after a missed period? I was predicted to start yesterday. Yes I know the app isn't the best indicator on when I actually start but I try to fill the information in correctly. Well I didn't start yesterday and so far this morning have seen no sign. I know the day has really just began so there still time. I noticed some red on my toilet paper when I wiped and a few "splashes" in the toilet but other than that nothing. When should I take a test? Today? Tomorrow? Next week? Please help I have no clue and I just want some advice or tips. Thanks