Unfortunately, no. You can check if they're been online since you sent it to see if they should've gotten it by now. But that doesn't guarantee they saw it. My inbox is pretty full, and I end up missing them all the time. They get buried. Some people take a long time to respond to pms as well. I'm guilty of this, especially if I want to take my time on my response. So, I wouldn't assume they're purposefully ignoring you. Maybe try again in a few days.
Edit: I think you get some kind of notice when you try to send a pm to someone who's blocked you. Not sure. Maybe someone can clarify.
