M20 skinny ectomorph. About to start to work out but noticed a sudden bulge and slight pain in my left tricep while doing push-ups. Right tricep feels normal—should I be worried?

I was about to start my workout today, and while trying to do push-ups, I noticed something unusual in my left tricep. I’ve only worked out for a few weeks before but stopped for a year. Now, while trying push-ups again, It looked like it had a bulge or swelling, and it felt a bit abnormal compared to my right tricep. There was also slight discomfort/pain. I’m concerned because this appeared suddenly, and I want to know if this could be related to muscle strain, overuse, or something more serious.