Could it be something bad if i have muscle pain?

It depends: Most muscle pain is benign- mild strain, overuse, soreness, etc. It often is mild and last only a few days. Severe and prolonged muscle pain is a concern. Severe would be pain 7/10 or greater and debilitating. Prolonged would be greater than 2 weeks. A muscle/tendon tear, inflammation of the muscle or something masking itself as muscle pain would be considered for severe and prolonged symptoms.

Normal or abnormal?: Muscle pain is a very common symptom. It can be related to muscle overuse, imbalance, or tightness. Muscle pain can, depending on where it hurts, your age, and other symptoms be related to a more systemic cause. See your primary care physician or a physiatrist to help differentiate.