Just be careful as a tender area which doesn't go away can mean infection, so always best to let the ob know straight away so they can check. I have had that with one pregnancy and tests were taken (swab) to check for infection (nothing showed up in the tests but my membranes ruptured prematurely with that pregnancy).

Another thing mentioned is the stretching of muscles supporting the uterus. With my current pregnancy I was having some intermittent very mild pain around the top of uterus on one side - only felt it when stretched out in bed or coughed, and it was there on and off for a couple of weeks and then went away altogether. When I described it to the ob they were pretty sure that one was ok.