I would say most definitely yes. As she is swollen then this is a sure sign. She may either be licking clean any discharge so you would not see it, or it could be what is termed a clear season. Please ensure you keep her away from any male dogs, and make sure she cannot escape from your house or garden, as she will be just as keen to find a fella as they are to find her! As you have not noticed the actual start, then she may be several days in, so could be 'ready' at any time. Can you carry her away from the house on walks, or take her out in the car, as this will stop local dogs from beating a path to your door. You are very lucky if she is such a clean little girl that she keeps herself totally clean.
Only other main cause of constant weeing would be cystitis, but doubt very much if this is the cause in this case.
If it were, cranberry tablets help clear it up.