Brownish discharge or spotting post ovulation?

Sorry if this is TMI... This is the first time this has happened for me. I confirmed ovulation using BBT and OPK. I'm 6dpo now and almost every day after ovulation, I notice either the following:

• brownish stringy discharge, something like what I usually observe before my period (but now I'm only 6dpo!). Most commonly observed these few days
• very very very watery discharge with yellowish tinge when I wipe.. it's not urine
• dried sticky/crusty brownish discharge on my underwear

I thought it was an infection but the discharge varies a little every day and I have no other symptoms.

I'm a little worried cos I know seeing brown/yellow in discharge means there's some blood. Although it's not a lot but it's happening every day...

Any idea what this could be happening? Is this even considered spotting?

If it helps this I did medicated IUI the last 2 cycles with oral progesterone after. This current cycle is unmedicated.