Girls, hello! After childbirth it's been 7 months, and on the 6th mont…

Girls, hello! After childbirth it's been 7 months, and on the 6th month after delivery, I started my period, everything went well, but the next month they didn't come, I took a test and found out I wasn't pregnant! I'm breastfeeding, is that normal? Is it okay with breastfeeding? Should I see a doctor? My stomach sometimes hurts, like it's about to start again, but no! Share your experience, did you have something similar? How soon will my cycle return to normal?