Constant pain😥

I am 27 weeks pregnant & I have been in constant pain since I was about 20 weeks. Stomach pain & back pain and pain in my stomach after going to the toilet (for a wee)
I have regular urine samples as normal & they always show up as being fine. I have had a few kidney infections which I found out when I went for a check up in hospital was put on antibiotics  etc and of course now the infection has gone "so the doctors say" as they can't find anything in my urine or on a ultra sound. The pain is really bad most of the time and stops me from doing my normal activities, even bending down, vacuuming or walking sometimes. I'm so sick of it it's getting me so down & I cannot enjoy my pregnancy at all. I worry the doctors are missing something which makes me worry for my own health but more so the baby! I just wish I could know what it is, surely it can't be normal pregnancy things like baby growing or it wouldn't cause me SO much pain!!😞🙁. I wondered if anyone else has been through a similar thing or if you have any advice!😕 it's so horrible to deal with! Thanks for reading! 😊