Welcome.
As oestrogen levels drop off so muscles may become lax = aches and pains. Sciatica is often due to bad posture, it happens to me if I fail to kneel when filling/emptying the dishwasher or laundry machines, if I fail to kneel when putting the dogs' collars/leads on, when gardening etc..
If it's sciatica your GP may suggest an X-ray of pelvis and hips to see if there's pressure. Can you describe it?