Advice please!

So I have birth control coming in the mail today (pill club). But here’s the issue, my period is 4 days late. I’m scared to start birth control because of that. But I’ve gotten 3 negative tests. Only one with fmu. That was this morning. But there’s not even a shadow of a line, it’s stark white. I can get in to see a doctor, it’s just a lot because of covid restrictions. The babies can’t come with me and doctors offices are open during the day, when I don’t have a sitter. I work nights so it’s opposite of my moms schedule and she can keep them. So I don’t have a day time sitter unless she took off work. And she would if I asked her to but I don’t want to ask. Should I wait and see if my period shows first? Or just assume the tests are right and start taking it? I’m nervous about the whole thing.

For reference: my periods have only been late when I was pregnant. They’re always regular. (To the point where both babies were born on the same day of the month, 3.5 years apart). My youngest is 5 months old. But I’ve had 4 regular periods since she’s been born. Is it possible for that to affect my period now when it hasn’t before?