Period help/opinions?

Hi . I ended my period a couple days ago. My periods are usually 4-5 days. Well ever since I ended, I’ve been still spotting Brown (which I know is old blood). So this has been going on for 4 days. This has never happened to me before. I haven’t had sex in a while so it’s not from that. I’m not on birth control or medicines. Has this happened to anyone before?

Looking for advice before I call my doctor.