If you do bruise easily you could have a vitamin deficiency or it could be something else and your body is giving you warning signs. Definitely something to just get checked out and mention to your doctor.
Thank you for your comments. No I haven't seen a doctor yet. I know the pain is from the popping of the vain, I just wanted to know the reason for that and why now happening frequently? Note that I am a kind of person who bruises easily even from small knocks or even scratching.
It would be worth mentioning it to the Dr, cos as seattlemom says it could be caused by a variety of different things, but this happens to me quite a lot, and all that happens to me is, I can knock wherever, and rather than damaging to bruising point, where the little vein/capillaries are broken, the vein wall weakens somewhat causing a bulge (like a teeny tiny hernia, but it's not!) The pain is when that bulge pops a few hours/days later, and then, obviously, it bruises (Buising being broken small veins/capillaries due to bumps or worse). And because it was a small bump to begin with, I can't remember doing it!
I have actually not heard of this, but it could be a variety of different ailments if you are bruising easily and having random pains. Have you gone to see a doctor about this?