Hello!
Avoid exercises which involve your biceps and rest your biceps muscle for a week. If your pain continues then you would need to go for some scans and a follow up near an orthopedician.
There might have been a sprain or tear involving your biceps muscle.
Take care!
Go see your doctor.
It could either be a tear that needs to heal (i.e. STOP working out) or tendonitis from repetition (like tennis elbow) that can become debilitating if left untreated. There's ways to beat bicep pain tendonitis, but you must ask your doctor, as some methods are suitable for some people and not for others. Don't just ignore bicep pain and keep working out; remember, bicep PAIN (not just the usual post-workout ACHE) is serious, and can even require surgery in some cases.