What Causes Stomach Pain And Clear Fluid Discharge After Periods?

Hello my name is kristi I'm 20 years old. Well my periods have been iregular for a couple months now 1 month id be 2 weeks late the next it would 2 n a half weeks late then last month its was 2 days late. It wasn't normal eaither I bleed heavy for the first day(may21 2011)then the next couple days it was couple spots here and there it ended may 27th. Now on may 21st I leaked a lot of clear fluid. And on june 4th I was having horible pain in my stomach and below my belly button it last for 3 hours then was dull pain for the rest of the day. Yesterday june 5th I started bleeding it was enough to fill a tampon and I had cramps but not like my usual period cramps(my period cramps are worse). And today I had a little bit of blood on a tampon . And not so much cramps today. I don't think I'm pregant I've took 3hpt 2 months ago and they were negitive. I have been feeling flutters in my stomach but I don't think I'm pregant. I have 2 boys now (2years aand 10months) so I know what its like to be pregant. This has never happened to me in the 7 years I've had a period. Nothing has really changed in my diet oor excerise and I'm not stress a lot. Just wondering what's goin on with my body.