Swollen Neck after Oral

So, a few days ago I gave someone head for the first time. He told me he was STI-free. The next day my throat wasn’t ‘sick’ sore — it just felt like the muscles were tender, which made sense because I did deep-throat him. I’ve had no trouble swallowing or anything like that. Today I noticed the right side of my neck feels a little puffy, though. Do you think I’m just being paranoid because it was my first time, or should I be worried?