Good evening, I am 7 weeks pregnant, a year after CS, is it normal tha…

Good evening, I am 7 weeks pregnant, a year after CS, is it normal that my lower abdomen often feels tight on the left side, but goes away when I lie down? Today, in the evening, the pulling pain in the lower abdomen on the left side came back, but also my back hurts as if during menstruation. I'm very worried, is this normal after CS or is it dangerous?