Neon yellow discharge?

I’m 8w6d postpartum and the past few days I’ve been having neon yellow discharge, but no foul odor. Not sure what it could mean. I’ve never experienced this before. Anyone else experience this? My ex (the father of my child) and I recently got back together, he says he didn’t sleep with anyone while we were broken up (for 8+ months), so I’m not sure if it’s an STI or not (him and I had unprotected sex two sundays ago). I’m going to try and see my midwife tomorrow so she can swab me and send it off to be tested.