Simple Question, simple answer!
As a physio who sees lots of ante-natal and post-natal patients, the best time I would love to see these patients is "ASAP - as soon as possible".
I like to screen the whole skeletal system, especially the pelvis, ensure good feeding posture and habits, good lifting and carrying techniques and start some gentle exercises to assist the likely abdominal muscle issues that at least 70% of women get.
Usually within the first few weeks, a new mother has some form of support with her - husband, partner, mother or mother-in-law are the most common people who attend with my patients. This is an ideal time as the new mother isn't chronically sleep deprived yet and there is someone else to hear all the advice and take care of the baby.
Once you are post-natal, you are post-natal for life!!!
Please remember that if your pain started since having children, it is never "too late" to start doing something about it. I have had women in their 50's and 60's tell me they wish they had seen me sooner.
So don't wait, book in to get checked now. If you don't have a physiotherapist you can trust, call us on +61 2 9585 8844 and we can help you locate one.