Girls, for several days now there's been a pulling sensation over the …

Girls, for several days now there's been a pulling sensation over the belly button, about 2 cm to the right. It feels like a muscle, but not exactly. Especially in the evening when I bend over... But it bothers me even during the day now, I didn't really strain myself today. When I press on that spot, I feel pain, kind of like a bruise... The doctor said that there's a muscle separation at that spot, and pains can occur. But it hurts not directly in the middle of the belly button, but rather slightly to the right above the belly button... Has anyone experienced this? What could it be?