During normal delivery all pelvic girdle ligaments get stretched resulting in post delivery pain/aches.
I would strongly advice you to wait for 6 weeks as they usually subside with simple pain killers.
Please make sure that the pain killers you use are safe during lactation
. Ask your gynaecologist for the same.
If the pain increases or persists after 6 weeks you must visit your physician or an orthopedic surgeon.