Contacts with iPhones are still texting/messaging my email address

I used to have an android phone and a macbook. I would use my apple ID (linked at the time only to my email) and the Messages app on my macbook to text iPhone users. I did this rarely in order to receive photos or not mess up group messages. Now I have an iPhone and the same macbook. However, some of my contacts are texting/messaging me, but I do not receive the message on my iPhone. I think they may only have my email on my contact info in some text message threads. Does that sound right/possible? Should I just tell certain contacts that I'm not getting text messages from to delete the contact info they have for me and start a new one somehow?

[Re-Titled by Moderator]