Clear the Ear. It's not unusual to experience pressure differentials in the ear when we swallow. The eustachian tube functions to control this process. If the pressure in the middle ear is too high and doesn't equalize with ambient pressure then the drum doesn't move properly and sound will not be transmitted effectively. The dull pain was likely due to the distention of the drum and will subside with time.
Get It Checked. It's possible this was just pressure equalizing in the middle ear, but there's also a chance you ruptured your eardrum (tympanic membrane). It would be best to have it evaluated by a trained professional, since in rare cases it can lead to hearing loss or balance problems. In the meantime, if it hurts, you can use a cotton ball in your outer ear (don't shove it in he canal) and use ibuprofen.