This is weird...ladies only.?

So i have one child and she was fed. She will be 3 in May I have fed her since she was 5 mths old. After that I still had some milk. ..but it went away last mth and this mth I have had like a sorta milky substance but I got my period and I have taken tests I'm not pregnant....I have just been to the doctor for a check up ( as they say you should before you ttc) and I was fine health wise..so its not an infection or some kind of infected discharge. Help me out. Please no guys(unless you know)...or insults...serious answers only. :-)