Cramping + Lower Back Pain

I’m 21 weeks 4 days and have had what started as a tightening turned to pain across the whole of my lower back. Now I also have cramps on thee right side of my uterus. If I lay on my right side or on my back within a few minutes the right side of my uterus will harden and raise. I’m in a good deal of discomfort and pain, making sleep difficult.

I don’t have any other symptoms that would indicate a UTI but may get tested for that in case. And I really can’t think what else it could be. Round ligament? Braxton Hicks? I don’t know. Any ideas?

Missing my home and husband as I’m away on business :(