Help! This could be baby #4 😱

Good morning!

So I’ve been on the Nuvaring since I had my son in March 2023. Well my husband just recently had a vasectomy this month. So I decided to take myself off birth control since I won’t be needing it anymore lol. I removed my ring 10/1 -10/8 which was my week free for me to start my period and I did. It’s been 3 weeks since my ring has been out. And we’ve been having sex since a week after he had his surgery. And I’m suppose to be getting another soon. Could this be implantation bleeding ?