Anyone know much about iPhones???

Melissa • Mummy to two coming 3 (due August) beautiful children.

So I had to block my boyfriends number tonight for various reasons..... but then suddenly recieved a notification that I have a new voicemail even tho my phone did not ring. I tried searching online asking this question and it's telling me no they cannot leave a voicemail yet some people are writing that they can as it's happened to them. Which answer is correct? Could it be him?