Severe upper abdomen pain that last about 30 mins

28w here too and I feel similar pains to yours starting this few days, but I can feel that it is due to my baby stretching out his legs plus sometimes kicking at my ribs.. sometimes last for more than 15mins. i keep rubbing that area and talk to baby and ask him to move away. and yes, back aches coming back too. this is due to the increase in baby weight & enlarged uterus we are carrying

It could be normal pain/pelvic pain/heartburn whereby when baby's growing and has limited pain you feel the aches and pains and long holding pains from pelvic area, back, ribs, heart, abdominal, crotch area. However, if it is a repeated pain that is unbearable usually, I will consult doctor and ask to check or share with me tips or prescribe cooling gel, etc to ease the pain.