Freaked out a little.

Hey all, is there a way to track a phone number for FREE? I've received a few face time requests from an unfamiliar number. In the past I had a very obssesive and abusive ex who used to harras call me from blocked numbers and I had to change my number multiple times and quit using social media. I'm worried he has somehow found my number out and is trying to reach me again. Is there any way to check a number for free? Or can someone check for me? I'm a little anxious and worried. Sorry for the long post. Please help 😕😭