other email so another person whose Apple ID is on my iPhone won’t see my messages. Will they still see it even if I switched off

so basically I have someone’s Apple ID on my iPhone because it was theirs now mine. I used iMessage today and i witches off the Receive and send to Toggle but it didn’t let me send anything so after a while I added my email to it and switched it off for them and turned it on to mine. I can send stuff but I don’t know if they can see my imessage. Help?