What is this?!

Dani • Hello! I am 25 and my BF is 30 and we are TTC a little bundle of joy! 😀

So a few weeks ago I noticed some spotting on my toilet paper. [AF is due tomorrow]

Today, I went to the bathroom and noticed a LIGHT brown discharge. It smelled like old blood.

I don't want to test just yet. Just curious if anybody else has ever experienced this? Opinions please!