Labour like Pain during Period & Groin Pains through the month off & on mostly after sleeping

My baby is just turning 4 months old. I have had 2 cycles since she was born. Before my cycles started (around 7-8 weeks after baby) I started with groin pains which happens sometimes several days in a row, or every few days. They are worse when I wake up in the morning after sleep. My first cycle was what I'd call normal. My last cycle was VERY bad! The first two days I had to stay in bed as the pains were "like labour pains" they would grab hold and double me over. Has anyone else experienced this?