Cramps All Month Long?

Does anyone else experience cramps all month long? 
For the last 3 months or so I've started experiencing dull cramps even when I'm not expecting my period. 
I've read that it could be something along the lines of endometriosis, and I do plan to see a doctor, but just wanted to hear if anyone has had similar experience. 
I'm 23. Not pregnant. Six months ago, my periods were completely normal. Since then, they have been much heavier, longer, and the cramps have been more intense. 
I would describe the cramps I'm feeling as dull and achy, like the cramps get right before you start your period... but I get them any time in my cycle.