What Causes Amenorrhea And Stomach Cramps After A Child Birth?

Hi. I am 6 months postpartum and been having slight cramping and bloating feeling. I also feel like my bladder is full. I have been feeling this for about a week now. I thought my menstrual cycle was returning but still no cycle. What does this mean. Me and my partner had intercourse a few times without protection. Could i be pregnant again?