Is a store bought pregnancy test accurate l?

Are store bought pregnancy tests accurate? Or should I go see a doctor? Which one would you do? I'm terrified to do either. And I'm even more terrified to talk to anyone about it. I don't have many people I can talk to about these things and even then it's still kind of awkward. When is the best time to do this? Like as soon as possible or do I wait to see if I missed my period? I'm clueless and scared. If there's anyone who has experience or knows what to do please help me.