I had it with this pregnancy before I found out I was pregnant. Actually told my OB that my uterus felt "heavy and swollen" he told me I probably had a UTI but that can back negative and 2 days later I found out I was pregnant. (We were told I wouldn't be able to have any more just a couple months prior to that by an endo so my doc never thought to check me)
I didn't ever really have any pains early in pregnancy, and I'm a ftm so I can't really tell you, but I'm interested to know as well and hope someone with a little more knowledge can give you an answer.