Someone punched me in the head 2 days ago. i have no symptoms at all but the side of my head (near the temple) is sore to touch. am i at risk of a hemotoma or something?

It is very unlikely to have an hematoma inside the Brain but it can happen.But you will have headache,Dizziness,nausea,vomiting and confusion.If you just have soreness at the site of trauma and otherwise feel ok.Then it is unlike to have a bleed inside head causing a Hematoma.If any of those symptoms consult your Doctor for further evaluation and if indicated imaging like Cat Scan

From what you say, you have suffered a closed head injury, and likely have scalp bruising, or small goose egg, which will be tender over a few days. There is no overt need to seek medical attention. Just avoid aggressive companions and raucous bars in the future.

If you did not lose consciousness and do not have dizziness, nausea vomiting, you are not at risk of serious untoward outcomes. If you get a skin swelling in the temple, it will resolve with time. Wish you good health!