Brownish Discharge (wk 36)

Hi I'm at week 36. I've been getting brownish discharge since week 35, it was clear after and then today it is brownish again (but lighter than week 35's discharge). 2 days ago I did had my cervix check so week 36's discharge could be due to the check(?) but at week 35 I hadn't had any appointment at all. Anyway I called the delivery suite the nurse said it was fine as long as no bright red blood and baby is moving. Anyone has any idea if this could be mucous plug? I really wonder what it is. Attached photos are my discharge since week 35. When I asked the gynae my previous appointment what it could she also couldn't really answer lol so I'm wondering any mummies has experienced something similar before.