It could be something that you are eating or maybe related to the hormones that are leaving your body. If it's worrying you a lot, best to ask your doctor. Try to eat some yoghurt or take probiotics meanwhile to improve your gut health, which might help with the situation.
It is not uncommon. This can happen after childbirth. It can be due to stool softener or due to indigestion too. If not too are, pls discuss this with you doctor.
High protein diet maybe? :) do drink liquids and keep yourself hydrated....ideally it should not persist long