Tripped Going Out To Take The Dog Out. There Is

Tripped going out to take the dog out. There is a very painful bruise (larger than an egg) on my leg and this evening I have had had 2 large blood blister rise from under the skin. I also take prescription blod thinner and am concerned about the looks of this. Should I go to ER? I am a x-large male, 65 years of age.