This does look like mucus plug but not necessarily an indicator of labour being close. If it’s your bloody show that’s a better indication of labour.
Your plug can re-generate over time. I had weeks of my plug coming out slowly. I never got a bloody show. But with you being 39 weeks, good luck girly!! You got this 💪🏻 (whenever it happens)
Looks like a bit of the plug!! Which means things are working in the right direction 🥰
My mucus plug looked exactly like this and I had my daughter the following day - good luck! 😊