What Causes Bruises All Over The Body?

hi I'm going to be 18 years old soon and I am about 5 foot 5 inches and about 110 pounds. I recently had mono about maybe 6 months ago and that's about the only major medical thing that has happened recently. Lately I haven be getting A LOT of bruises all over my body and in very odd places. I don't recall getting them in any way and most of them are very small circular dot like bruises. What is this and why am I getting them?