Hi mama! Chest or rib pain for more than a week at 28 weeks is something you really need to check with your OB or go to the hospital, hindi kami dapat mag-assume dito kasi pregnancy can be unpredictable talaga, and it's better to be safe. A few of us mums experienced rib pain from the baby's position or just pregnancy changes, but puwede ring iba ang reason mo, so please don't wait pa, get it checked ASAP para peace of mind mo at baby mo. Sending you strength, first-time mama!