6 DPO and cramps?

Today I am 6 DPO and for the past couple days I have been having cramps ranging from very mild and dull to flat out painful. Last night I woke up because I was cramping really hard every time I moved in bed. This is not normal for me to cramp way before AF is due, as I normally don't cramp until the day AF shows her ugly face. I also have a small bump in my lower abdomen and it's very tight feeling and hard where my ovaries and uterus is. Anyone else experience this? Does this mean anything at all?