Here are some ways to tell if your waters have broken from the BB article Labour Signs: Could I Be In Early Labour?:

Some indicators that your waters that have broken are:

Having no control over the flow
A panty liner is inadequate to absorb the fluid
The pad is wet more than once, and
It doesn’t smell like urine

Some women describe their waters smelling a bit like ‘semen,’ so if you do notice a smell, mention this to the midwife. Your waters should be clear or may have a pink tinge to them. If they are green, brown or any other colour you should get checked out by your doctor or midwife.
When you labour establishes the contractions will become regular and stronger - I would say its still early yet. If you like, check your temperature from home to see if you notice your temp going up (sign of fever or infection). If you notice it I would ring. So see if you think you are in that group above, and decide from there, and be aware if you go to hospital they may want to augment your labour. You can however agree to antibiotics if your waters have broken with no labour, so you can have the chance to labour naturally. As you will likely know, Strep B is transient so you may have been positive at your swab weeks ago, but negative now. You can also have AB's if you show sign of infection.