Mine started around 21 weeks, after standing all day at an engagement party. My pelvis clicks and clunks, and is painful most of the time - walking, stairs, anything on one leg, and particularly rolling over in bed. My husband (a physio) bought me a brace and with that on I can do more things like go for a walk, gardening etc etc. Doesn't get rid of the pain completely, but at least allows me to do normal things.