Since you have exercised 3 days ago, that could be a muscle sore. For now, apply icing and stretch particular muscle. ( refer specific muscle stretching at youtube) Try achieving all movement of shoulder. (Dont limit movements) PS: Make sure you always warmup before exercise and cool down. Else this is expected repetitive.

May Be You Have Injured Your Biceps Muscle It May Due To Heavy Workout Visit Some Physiotherapist Near To You

Hey . There can be two reason either muscle pull or overuse syndrome . This can happen when u start your work out without doing proper warm up ex or u might have not given proper rest interval between sets mor may be because of some improper cool down period and In both the cases initially u should go for ice massage and avoid doing exercises . Later u can start with light exercise and progress step by step to weighted ex

Concentrate on your work out position/Repetitions etc when you do work outs.Try and get a Musculo-skeletal physiotherapist nearby if you continue to have the same problem again and again

Do some warm up exercises , free Range of motion exercises before  lifting the weights. Apply a hot pack half hour before doing the exercise

Contrast Fomentation (Hot and Cold).

Consult with physiotherapists near you.

Ur pain in the arm maybe Bez of biceps strain. Usually this happens when your muscles around Ur shoulder joint called as rotator cuff muscles are weak and Ur biceps/triceps/deltoid are very strong. This causes muscle imbalance which leads to injury. Please do twice or thrice icing of Ur forearm n biceps. Avoid any stretching exercises and lifting of heavy weights for now.

Hai this is. Not at all an injury since gymgoers usually have pAin and more over u didn’t tell whether u do gentle warm up exercise or not before going to do weight . If not then it is ur problem kindly do the exercises with. A help of a coach otherwise u will land up n this kind of problem alway remember low weigh maximum repetition and maximum weight minimum repetition all the best