I am terrified - am I pregnant?

I had sex around a week ago, and my period is to start relatively soon (but I’ve had instances in the past where it takes much longer than a month to cycle). I had brown discharge - not a lot, but enough to make a mess in my underwear. I wore a pad for a day and nothing. This has happened about once a day for 3 days. I don’t know if it’s the stress but I’ve also had a stuffy throat (feeling like I need to vomit) and a loss in appetite. My parts have also been a little itchy. I’ve also had a poor sleep schedule as of late, if that matters at all.

I’m not ready to have a child if this is the case. For those saying to buy a test, I’m so terrified of the result that I just can’t.

What do I do?