HELP Has anyone here had constant abdominal pain when pregnant??

I have had constant abdominal pain and discomfort since 6 weeks, and I’m now 11 and a half weeks pregnant. I’ve been to the ER and none of my tests showed anything off. I’ve told my OB, but he keeps saying he doesn’t know what it is, and that it’ll probably go away when I’m 13 weeks. I really hope it’s true, but it has not improved at all. I’m really suffering, and I can’t find any info online of anyone else who has experienced this. Has anybody else here had constant abdominal pain when you were pregnant? Did it ever go away?