Breasts leakage can appear after a miscarriage but usually for a short period of one week.
When the leakage happens from the two breasts, the cause is usually systemic (affecting the whole body).
It is very possible that you are experiencing some endocrinal disorder (hormones disbalance, thyroid gland disorders very often follow pregnancy) that cause breasts leakage.
Also, if you are on some birth control pills, it could be a side effect of the pills.
Try to avoid breast stimulation.

Visit your physician!

Most of the time, Breast leakage is normal. Depending on the color of the discharge. If it is of light color, it is normal but if it is colourful, it is not normal. Women have known to have breast dischages long after having given birth. The worst I am aware of, she did have it 3 years after. Make sure there is no smell and the color is light.

If it is colourful, it may be the fact that you wear underwire bras and you are cutting out your mammary glands and they are letting you know that your are causing some problems with your bras.

Good luck