Hello and thanks for your  post,

Whenever anyone complains of a symptom that does  not go away then we always advise them to get it checked out by their GP.  We can't diagnose you (tell you what is wrong).

It may well be a benign cyst (not cancer) such as a Bartholin's cyst which can appear just  inside the opening to the vagina. You can read more about these here

I can't say the cause of your spotting but it may still be your body readjusting after your birth.

I would make an appointment with your GP to mention your periods and the spot on your vagina.

I hope this helps.

All the best,

Catherine