Camping at 22 weeks... help!

I know this may be a dumb question but I’m a FTM and I just don’t know. I’ve been having some cramping the last four days in my lower abdomen. I thought I was nothing more than my uterus expanding. The night after it started I went camping, slept in a tent and had a pretty active day. Yesterday I noticed that I’m now having some pain all around my uterus and back. I have a midwife appointment today at 2:30 but if it’s something serious I should go to the ER. Is this normal? Should I be concerned? Please help 😢