I only get my period every 3 months since i had an abortion on october 8th. 2011. its a heavy period with clots. should i be worried?

Maybe.: Normal ovulation (releasing an egg from one of the ovaries) "sets the timer" that determines when your next period will occur, typically around 14 days after ovulation. The longer you go between ovulations, the further apart your period, and the heavier your period will tend to be. You are probably ovulating only once every 3 months, or not ovulating at all.