Semen or EWCM?

What color are sperm/semen after it comes out a women's vagina? S/O came in me, and the next day at night (note: NIGHT) I had egg white discharge when I wiped.

I'm not sure if it's EWCM or old sperm that came out when I wiped. (It was clear, my cheap opk stated neg).

Do you think it was fertile EWCM or old sperm?

Also, since Friday I've had these discharge found on the toilet paper; I just had a blob of ewcm once only.