Back pain?

Does back pain always mean miscarriage? The past few days I've been having some sharp lower back pain just on and off. Had an ultrasound a few days ago and showed the heartbeat and that baby was okay. Just kind of started spotting some light light light light brown. Barely brown, it's like a tan color. Just mild cramps on and off. I've had a mc before that's why I'm freaking out 😕