Small red dot/blister
on the ear drum can be because of myringitis which is viral infection of the ear drum and resolves on its own or with steroid
ear drops. The other cause can be intramembranous bleed because of some trauma during self cleaning of ear which also resolves on its own. Red area on tympanic membrane along with pulsatile beating in ear should be investigated radiologically for any vascular tumour in the middle ear, although the incidence is very less. Please get your blood pressure monitored regularly. Should see your ENT if the symptoms persist.