Should I invite him to the scan or not?

I recently blocked my ex who I'm pregnant by on all social media so he cannot get in touch with me due to the stress he was putting me through. He wasn't stopping drinking all of the time and smoking weed. And it seems like he wants to hide that he has a baby on the way so he can keep his girlfriend. Before all this he had came to my very first scan at 9 weeks and he was meant to be coming to my next one in 2 weeks. The thing is all I wanted was for him to be there and involved with the baby. I wanted him to be at everything and he said he wanted to be too. Im not making any decisions right now.. But I'm debating whether closer to the time I should unblock him and give him the offer of still coming to the scan? Or do I just not get in touch with him so he can learn that he needs to get his priorities right so he can be involved with his child. I just don't know what to do because I don't want to get in touch with him so he knows I'm serious that he needs to change to be in the baby's life, but then I feel bad and I will regret if he isn't there at my 12 week scan. What do you think I should do?