I’m a little nervous

I was supposed to come on 4 days ago but I had some bleeding so I thought I came on. But here we are 4 days later no blood on the pad but a little brown discharge or dried blood but a little blood when I wipe. Today my lower back has been hurting so bad like I worked out or something and I get slight cramping. Do I take a pregnancy test or do I wait it out ? I’m nervous and idk what to do 😭😭please help