Ghusal

Seeing yellowish discharge when waking up

Q: My periods are always on time and even the bleeding will be for 6 days and I will take ghusl. Due to some physical ailments my regular vaginal discharge is yellowish in colour. It is like regular vaginal discharge but instead of white it is yellowish.

My question is, as this yellowish discharge is regular and after waking up from sleep I find this yellowish discharge daily, when I am certain that I didn't have any wetdream during sleep then what should I do? Is ghusl necessary due to this yellowish discharge which is continuous during the day as well as during the night.

Note: I am certain that there was no wetdream or lust during sleep.